Error: ‘partfile_write Access Denied’ when selecting partial content within a Torrent (v4.6.5)

[Rubber-Duckie]

Error: ‘partfile_write Access Denied’ when selecting partial content within a Torrent (v4.6.5)

[glassez]

Here is an example torrent to try, this has multiple files within it.

No problem with it.

Keep in mind that if the application does not work correctly in some case, it does not necessarily mean that the problem is with this application. At least there are some specific conditions in your environment that cause this problem. And it would be nice for you to try to figure it out better before you say something like "This app is seriously broken" out loud.

[Rubber-Duckie]

Possibly related #18410 , #19048

[Rubber-Duckie]

Error

There are errors seem related and lead up to the access denied error, see below.

(W) 2024-05-15T14:28:27 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:27 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:27 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:27 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:28 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:28 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:28 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:28 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:30 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:30 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:30 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:30 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:31 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:31 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:31 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:33 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:33 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:33 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:34 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:34 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:34 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:36 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:36 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:36 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:37 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:37 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:37 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:39 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:39 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:39 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:40 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:41 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:42 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:42 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:42 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:42 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:42 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:43 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:43 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:43 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:43 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:43 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:44 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:44 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:44 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:44 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:45 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:45 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:45 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:45 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:45 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:46 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:46 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:46 - Unexpected data detected. Torrent: SomeTorrent. Data: total_wanted=10340482053 total_wanted_done=10340483072.
(W) 2024-05-15T14:28:46 - File error alert. Torrent: "SomeTorrent". File: "F:\SomeTorrent\SomeSubFolder\SomeFile1.!qB". Reason: "SomeTorrent partfile_write (F:\SomeTorrent\SomeSubFolder\SomeFile1.!qB) error: Access is denied"

[Rubber-Duckie]

Update; If I then go back into the content tab, then ensure I check/select ALL files within the torrent, then click resume. The missing files proceed to download and the torrent finally completes as normal.

[Rubber-Duckie]

Not sure if this issue shown below is linked, but I noticed a progress bar suddenly spread across all columns, seems to be another bug on the progress bar, lasted 10 seconds or so before it then converted to "Completed".
Possibly due to Progress Remaining registering as "unknown" for some reason, not sure.

This is happening also if you keep resuming a torrent with partial content selected for download after it has stopped due to the aforementioned error. Notice the last file, despite the Priority set to "Do not download" at the get-go, the Progress bar suddenly bugged out. (The file was actually downloaded too!!)

[glassez]

It seems the engine is in conflict with the user content selection criteria, since "SomeSubFolder" does not exist on disk, which is expected, but the file engine is still attempting to download and save to the folder regardless, hence the error.

For me it looks like your torrent has cross-file piece that matches both "unselected" and "selected" files but qBittorrent (namely libtorrent) couldn't write unused part of such a piece in .parts file for some reason thus partfile_write error is raised.

Not only that, but "Access is denied" is in fact the wrong error anyway, as one would expect "folder does not exist".

Given the above, I would not dismiss "Access is denied" as the real reason for the error. Are you sure that the current permissions allow you (qBittorrent) to create files in the root of the disk F:?

[Rubber-Duckie]

For me it looks like your torrent has cross-file piece that matches both "unselected" and "selected" files but qBittorrent (namely libtorrent) couldn't write unused part of such a piece in .parts file for some reason thus partfile_write error is raised.

This happens with any torrent containing multiple files. You change one or more of the content (files) to priority "do not download" and the error occurs.

Given the above, I would not dismiss "Access is denied" as the real reason for the error. Are you sure that the current permissions allow you (qBittorrent) to create files in the root of the disk F:?

It does have full permissions to create files. Keep in mind, if the application did not have permissions to read and write to the target directory or its cache directory, it would not be able to start the torrent. It would not download parts of the torrent. This is about the setting of some of the files within a torrent to the priority "do not download" and those files causing the error. When the Torrent is in the error state, the only way to continue is to set the files you prioritised to "do not download" to any other priority i.e. normal, high or maximum. Then the torrent will continue to download to completion.

[Rubber-Duckie]

Here is an example torrent to try, this has multiple files within it. It seems to be a copy of the audio from shows on you tube. https://www.youtube.com/@howardstern/videos

magnet:?xt=urn:btih:6cfe0714aa4363fd6cb123395e7d62e6f1d3f837&dn=Howard Stern Interview Pack 2 [Dbaum2]&tr=udp%3A%2F%2Fopen.stealth.si%3A80%2Fannounce&tr=udp%3A%2F%2Fexodus.desync.com%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.cyberia.is%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337%2Fannounce&tr=udp%3A%2F%2Ftracker.torrent.eu.org%3A451%2Fannounce&tr=udp%3A%2F%2Fexplodie.org%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.birkenwald.de%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.moeking.me%3A6969%2Fannounce&tr=udp%3A%2F%2Fipv4.tracker.harry.lu%3A80%2Fannounce&tr=udp%3A%2F%2Ftracker.tiny-vps.com%3A6969%2Fannounce

Select only one of the files;

Observe the error;

Then change all the files to normal priority and click resume. Torrent now downloads.

[glassez]

Given the above, I would not dismiss "Access is denied" as the real reason for the error. Are you sure that the current permissions allow you (qBittorrent) to create files in the root of the disk F:?

It does have full permissions to create files.

Would you mind to run the following command in PowerShell and provide its output?

Get-ACL -Path F:\ | Format-Table -Wrap

[Rubber-Duckie]

I have removed that comment, good point.

I have executed the script;

[Rubber-Duckie]

You are right!
The permissions are indeed unusual. Typically, built-in users should be granted modify rights, not merely the ability to create files.

The file storage permissions had been customised in an unconventional manner which masked the issue, since the user can still create and delete files and folders.

After resetting the directory permissions to their standard configuration, we’re now seeing the expected behaviour.