Fix transfer and resume errors
For:All users
No technical knowledge required.An interrupted attempt does not automatically mean that completed destination files are lost. WolfP2P can offer the set again, verify completed destination files with SHA-256 evidence, and—in Safe mode on a supported browser—resume a verified large-file prefix from its last durable checkpoint.
Open the question matching your problem, or find the exact code shown by WolfP2P. Each answer quotes the current English message. Review Transfer Recovery and Reliability for the complete Safe mode, Quick mode, checkpoint, and content-verification rules, or see the definitions of offer, file set, and checkpoint.
Preserve recoverable progress
Keep the original source and the receiver's destination until WolfP2P confirms durable completion or explains the safe recovery point. Follow the participant-specific action shown in the current panel rather than assuming every interruption requires a complete restart.
A transfer stopped or did not start
What happens if the receiver declines the offer? TRANSFER_DECLINED
The receiver declined this transfer offer.
The receiver chose not to accept this offer. Confirm that you sent the intended files to the intended person before offering them again. A decline is not a connection fault.
What should I do when a transfer fails? TRANSFER_FAILED
The transfer ended before it completed.
Check both computers for a more specific message, correct that problem, and use the recovery action offered. Keep the original files and destination progress; a failed attempt does not mean all completed files must be sent again.
Can I recover an interrupted transfer? TRANSFER_INTERRUPTED
The transfer was interrupted before durable completion.
Keep both tabs open and restore any lost connectivity or file access. Use the recovery action shown. If a new tunnel is needed, offer the same set and select the same destination so WolfP2P can verify reusable content. See recovery limits.
Why did the transfer end after being idle? TRANSFER_IDLE_EXPIRED
The transfer ended after making no confirmed progress within the allowed time.
No confirmed progress arrived within the allowed time. Check that both people are present, both computers are awake, and no permission or destination decision is waiting. Then use the available recovery or new-transfer action.
Why did the transfer time out with no progress? TRANSFER_PROGRESS_TIMED_OUT
This attempt stopped because no transfer progress was confirmed in time. The sender can start recovery while the transfer is still available.
Check both panels for a waiting permission prompt, destination problem, or lost connection. Keep the source and destination. The sender can start recovery, and the receiver should then follow any local permission or destination request. The transfer’s overall lifetime continues while recovery is attempted; a moving network indicator does not confirm saved progress.
What if the transfer reaches its maximum duration? TRANSFER_LIFETIME_EXPIRED
The transfer reached its maximum lifetime before completion.
This attempt cannot continue beyond its lifetime. Follow the panel’s next action to offer the files again. Preserve destination content for verification; restarting an attempt does not necessarily mean resending every completed file.
What if recovery takes too long? TRANSFER_SUSPENSION_TIMED_OUT
Automatic recovery stopped when the suspension allowance expired. The sender can start recovery while the transfer is still available.
The automatic attempt stopped, but that alone does not mean the transfer’s overall lifetime or saved progress expired. Keep the source and destination. The sender can start recovery; the receiver should wait for that action and then restore destination access if requested.
Why does this browser say it has already finished? TRANSFER_COMPLETED_LOCALLY
This browser has already completed its local transfer work.
This browser has no more local transfer work to perform. Check the overall result and the other participant’s status before closing the session. Local completion alone should not be treated as confirmation of the other browser’s outcome.
Are my files saved if durable completion is not confirmed? TRANSFER_NOT_DURABLE
The destination could not confirm durable completion.
Do not treat this attempt as complete yet. On the receiving computer, check storage, access, and the current recovery message. Keep the original source until WolfP2P confirms that the destination has been durably saved and verified.
What should I do with an unexpected error? UNEXPECTED_ERROR
WolfP2P encountered an unexpected problem.
Keep the source and destination. Follow the recovery action shown, and avoid reloading while useful recovery is in progress. If the same action repeatedly fails, note the code, both browser versions, and what you were doing, then report the problem.
Resume and content verification
Why can’t WolfP2P reuse the saved file prefix? TRANSFER_CHECKPOINT_MISMATCH
The saved checkpoint does not match the source content.
The saved checkpoint does not match the source content. Do not force resume from it. Keep the intended source unchanged and follow the panel’s restart or new-offer action so destination content can be checked again.
What if the received content does not match the source? TRANSFER_CONTENT_HASH_MISMATCH
The completed destination content did not match the source verification value.
Do not use the affected destination file as a verified copy or delete the original. Keep the source unchanged, check drive and file access, and follow the offered recovery action. A repeated mismatch should be reported; it is not a malware-scan result.
Can I skip verification if the browser cannot perform it? TRANSFER_HASH_VERIFICATION_UNAVAILABLE
Content verification is not available for this source or destination.
Do not assume an existing or received file is verified. Restore readable access to the source and destination and follow the panel’s available action. Check browser compatibility if verification remains unavailable.
What if the completed destination could not be verified? TRANSFER_DESTINATION_VERIFY_FAILED
WolfP2P could not verify the completed destination content.
Keep the source and do not treat the destination as a verified copy yet. Check that the receiver still has access to the file and drive, then use the offered recovery action. This message does not itself say that the contents differ; the verification operation could not finish.
What if this browser forgets which transfer it was recovering? TRANSFER_RECOVERY_CONTEXT_LOST
This browser no longer holds the record of which transfer it was recovering, so that transfer cannot be resumed. Files already received are still where they were saved.
This is not a missing folder or a refused permission, and choosing files again will not answer it: what is gone is the identity of the transfer itself, so there is nothing left to resume into. Close the outcome and start a new transfer. Anything already written to the destination stays there, and the file list and transfer report remain available wherever this browser still holds them.
Why doesn’t saved progress match the offered files? TRANSFER_RESUME_MANIFEST_MISMATCH
The saved transfer record does not match the offered file set.
Check that the sender selected the intended original file set. If names, sizes, or the set changed, use a new offer instead of applying an unrelated saved record. The receiver should review that offer and destination.
What if the saved progress cannot be used? TRANSFER_RESUME_NOT_APPLICABLE
The saved progress cannot be applied to this transfer.
Use the current panel’s restart or new-offer action. Preserve destination files: WolfP2P may still verify completed files for reuse even when this particular saved progress record cannot be applied. See what recovery preserves.
Why did preparing my files run out of time? HASH_PREPARATION_TIMED_OUT
Source preparation stopped after five minutes without new progress. The sender can try again while the transfer is still available.
WolfP2P stopped receiving measured progress from source preparation for five minutes. Large files can take longer overall while progress continues. Check that the source drive is connected and accessible, then try again while recovery is offered. The timeout alone does not identify the cause of the stall.
Why did the selection or offer window end? OFFER_TIMED_OUT
The waiting window ended. Start a new transfer when both participants are ready.
Choosing files, answering an offer, and retrying before acceptance have a twenty-minute human wait. Once source-folder enumeration starts, five minutes without new progress ends that work. Start again when both participants can continue. If files were already saved during an earlier attempt, keep them for verification and reuse.
What if an interrupted transfer was not picked up in time? TRANSFER_RECOVERY_TIMED_OUT
Recovery preparation stopped when its time limit expired. The sender can start recovery again while the transfer is still available.
The current recovery-preparation attempt stopped. The sender can start recovery again while the transfer remains available. Keep the source and destination; this expiry alone does not end the transfer’s lifetime or delete saved progress.
What if the tunnel says complete but this side does not? TRANSFER_COMPLETION_NOT_OBSERVED
The tunnel closed as complete, but this side did not confirm completion.
The two sides disagree about whether the transfer finished. Do not assume either answer. Open the file list to see exactly which files were written here, and check the same list on the other computer before deciding whether anything needs sending again.
Messages the two browsers cannot safely use
What if the browsers use incompatible protocol versions? PROTOCOL_VERSION_MISMATCH
The two browsers are using incompatible protocol versions.
Both participants need compatible versions of WolfP2P. Preserve source and destination files; once this stopped session is no longer recovering, reload the official site on both computers and establish a new tunnel.
What if the transfer protocols do not match? TRANSFER_PROTOCOL_MISMATCH
The two browsers cannot continue because their transfer protocols differ.
The browsers cannot continue this attempt together. Preserve the files, reload the official site on both computers after this stopped attempt, and establish a new tunnel. Do not bypass the compatibility check.
Why was an incoming file chunk rejected? TRANSFER_CHUNK_INVALID
The transfer received a file chunk that did not match the protocol.
The received chunk did not meet the transfer protocol. Do not assume the current file is complete. Keep the source and use the recovery action shown. If it repeats with both browsers on the current site, report the error.
Why was a content-verification value rejected? TRANSFER_CONTENT_HASH_INVALID
The received content-verification value was invalid.
The verification value was invalid, so it cannot prove that the file is correct. Keep the original and use the panel’s recovery action. If it repeats, report the error with the code and browser versions.
Why was a file position or size rejected? TRANSFER_FILE_RANGE_INVALID
The received file position or size is outside the offered file range.
The received data refers to a position or size outside the offered file. Keep the source unchanged and follow the recovery action shown. Do not treat the destination as complete just because some bytes arrived.
Why couldn’t a verification request be used? TRANSFER_HASH_REQUEST_INVALID
The content-verification request did not match the active transfer.
The request did not belong to the active transfer’s expected verification work. Follow the available recovery action and preserve the files. Repeated failures on current browsers should be reported.
Why couldn’t a verification response be used? TRANSFER_HASH_RESPONSE_INVALID
The content-verification response did not match the active transfer.
The response did not match the active verification request. Do not count it as evidence of matching content. Follow the panel’s recovery action and report repeated failures.
Why does a message belong to a different transfer? TRANSFER_ID_MISMATCH
The received message belongs to a different transfer.
WolfP2P rejected a message for another transfer. Use the current panel’s available action and avoid controlling the same saved session from extra tabs. If it repeats, retain the code when reporting it.
Why is an offered entry too large for the file list? TRANSFER_MANIFEST_ENTRY_TOO_LARGE
A transfer entry exceeds the supported manifest limit.
This is a limit on an entry in the transfer description, not necessarily on the file’s byte size. Note the affected entry and code, and report the problem if you cannot offer it. Do not assume changing large-file mode fixes this limit.
Why was a transfer message rejected as invalid? TRANSFER_MESSAGE_INVALID
The received transfer message was invalid.
The browsers cannot safely use this message. Keep the files and follow the recovery action shown. If it repeats after both browsers load the current site for a new session, report it.
Why was a transfer message too large? TRANSFER_MESSAGE_TOO_LARGE
The received transfer message exceeded the supported size limit.
The protocol message exceeded its supported limit. This does not by itself mean the selected file is too large. Keep the files, follow the available next action, and report repeated failures.
Why was the Safe or Quick mode value rejected? TRANSFER_MODE_INVALID
The received Safe or Quick mode value was invalid.
The received mode value was not valid. Use a mode offered by the current panel when starting again; do not attempt to override it. If both browsers use the current site and this repeats, report it.
Why doesn’t the transfer plan match the offer? TRANSFER_PLAN_INVALID
The received transfer plan does not match the offered files.
WolfP2P cannot safely apply a plan that disagrees with the offered files. Keep the source unchanged, review the intended set, and follow the panel’s recovery or new-offer action.
Why was my file offer rejected as invalid? TRANSFER_PROPOSAL_INVALID
The transfer offer was invalid or incomplete.
The offer was incomplete or invalid. Check the intended source selection and use the new-offer action when available. If it repeatedly fails with the current site on both browsers, report it.
Why did this browser receive work meant for the other participant? TRANSFER_ROLE_INVALID
This browser received transfer work for the wrong participant role.
The transfer message does not fit this browser’s sender or receiver role. Follow the current panel’s recovery action. If it repeats in a new session, report the code and describe which computer was sending.
A local report could not be saved
Did my transfer fail because report information is missing? TRANSFER_REPORT_CONTEXT_MISSING
WolfP2P could not save the report because its local transfer context is missing. The transfer outcome is unchanged.
No—the report-saving problem does not change the transfer outcome. Check the transfer result separately. If reporting the issue, include this code and the result shown; the missing local context may prevent saving this report.
What if the local transfer report could not be saved? TRANSFER_REPORT_SAVE_FAILED
WolfP2P could not save the local transfer report. The transfer outcome is unchanged.
The transfer outcome is unchanged. Check the result shown in the panel rather than sending the files again just to create a report. Keep the error code if you need to report the missing record.
What if the report update did not finish? TRANSFER_REPORT_TRANSACTION_INCOMPLETE
The local report update did not finish. The transfer outcome is unchanged.
Do not repeat a successful file transfer merely because its local report update failed. The transfer outcome is unchanged, but the report may be incomplete. Use the panel result and keep this code if you need support.
The problem is on the other computer
What if the other browser has lost file access? PEER_ERROR_FS_PERMISSION_BLOCKED
The peer's browser does not have permission to access the files needed to continue.
Ask the other participant to follow the permission message on the other computer and grant access to the intended files or destination. Changing permissions on your computer will not restore access on the other one.
What if the other person cannot open a chooser? PEER_ERROR_FS_PICKER_UNAVAILABLE
The peer's browser cannot open the file or folder chooser needed to continue.
The other participant needs to open the official site directly in a browser with the required chooser. The other participant can check browser compatibility. Opening a chooser on your computer will not resolve that limitation.
Who needs to make more storage available? PEER_ERROR_STORAGE_QUOTA_EXCEEDED
The peer's destination does not have enough space to continue the transfer.
The destination on the other computer needs attention. Ask that participant to check drive space and browser quota or choose another destination. Do not delete your source copy to address a storage problem on the other computer.
What if a file operation failed on the other computer? PEER_ERROR_TRANSFER_IO_FAILED
Reading or writing a file failed on the peer's device, so the transfer stopped.
Ask the other participant to read the more specific local message and check the source or destination access, drive connection, and available storage on that computer as applicable. Use the recovery action after that issue is resolved.
What if the other person lost a place in the tunnel? PEER_ERROR_SEAT_DISCONNECTED
The peer’s place in the tunnel ended when that browser’s connection to the service did.
The other browser lost its live service attachment. Its reserved seat may still be recoverable, and this message does not establish an intentional departure or a retired tunnel. Follow the current panel while the owning browser reconnects.
What if the other person moved to another tab? PEER_ERROR_SEAT_RECLAIMED
The peer moved to another tab, which reclaimed that place in the tunnel.
The person is still there; the tab you were paired with is not. Nothing is wrong on your side. Wait for the new tab to reconnect, or agree a new tunnel if it does not.
What if another tab took over the other participant’s seat? PEER_ERROR_SEAT_TAKEN_OVER
Another tab took over the peer’s place in the tunnel.
A replacement connection holds the other participant’s seat. Wait for that browser to reconnect and follow the panel’s recovery action. This message does not provide or prove a transfer of recovery authority to another device.
What if the transfer failed on the other computer? PEER_ERROR_TRANSFER_FAILED
The transfer ended in failure on the peer’s side.
The record carries no further reason, so nothing more specific can be said about it. Whatever was written before it stopped is still on your disk. Ask the other participant what appeared there, and offer the same set again when the other side is ready.
What if the other side says finished and mine does not? PEER_ERROR_TRANSFER_COMPLETION_NOT_OBSERVED
The other side treated the transfer as finished while this one did not.
The two computers disagree about the outcome, and neither answer should be assumed. Compare the file lists on both sides. Anything missing here can be offered again; WolfP2P verifies what already arrived rather than resending it.
What if the transfer was interrupted on the other side? PEER_ERROR_TRANSFER_INTERRUPTED
The transfer was interrupted on the peer’s side.
An interruption is the recoverable kind of stop, but whether it can still be picked up depends on the state your own session is in. Check what the panel offers you now. If recovery is not available, offer the same set again.
What resume can and cannot preserve
Completed files can be skipped after path-and-size candidate discovery and SHA-256 content verification.
Safe mode can resume a large file from its last acknowledged destination checkpoint.
Quick mode restarts the interrupted current file from its beginning.
Reloading or browser-restoring the same tab can preserve its session; genuinely closing the tab ends it.
Both peers must be online while file bytes are moving.
Relative path and byte size identify possible destination matches, but SHA-256 content or prefix evidence must verify a reusable result before WolfP2P skips or resumes it.
Mid-file checkpoint resume requires the receiver to use Safe mode. Safe mode may need about twice the file's size in free disk space, and an interruption can require retransferring up to approximately 256 MB of the current large file.
One browser tab represents one tunnel. Reloading or browser-restoring the same tab can resume its session, but genuinely closing the tab ends that session.
Both peers must remain online while file bytes are moving.