Cannot Access CBR or CBZ Files Because of File Being Used by Another Process

[calibreian]

Hi all,

I'm having an error trying to open CBR files via Calibre. I've seen this question asked in one or two other places on the web and I asked on Reddit but got no solution. EPUB and PDFs are working, but not CBR or CBZ. Here's the error when trying to access via Firefox over network:

Traceback (most recent call last): File "calibre\srv\books.py", line 127, in job_done Permission Error: [WinError 32] The process cannot access the file because it is being used by another process: '\\?\C:\Users\Username\AppData\Local\calibre-cache\srvb\s\stkhp40k' -> '\\?\C:\Users\Username\AppData\Local\calibre-cache\srvb\f\0e3331f92ac8026a750dbf4fd0280b385c200 74a'

My Calibre library is not on the network, it's in C:\Users\Username\*, I've tried it in a few other places as well, the same message pops up. I've used ProcessManager and Powertoys File Locksmith and neither say the folders/files are being accessed by anything else. I've allowed Calibre-Parallel.exe through the firewall and have no alternate antivirus software or OneDrive.

Also, from what I know of how Calibre works, when a CBR is accessed, it creates files in the appdata cache folders that contain the entire CBR as JPG files. Though every time I try to open a CBR, including books that have already been opened, it recreates those JPG files in a new cache folder each time, which seems counterintuitive, as some CBRs are 200+ MB, which quickly makes the cache folder 1+ GB. This functionality seems incorrect, meaning I must have something wrong that coincides with the error I'm seeing. There are also two Calibre Worker Processes running in the task manager, though if I kill either one, it doesn't even passed the loading screen of the book - not sure if this is related.

Any help would be greatly appreciated! I'd love my books to be accessible.

[BetterRed]

Have you tried version 8.5, some recent changes maybe germane.

IMO - the best solution is to not use the calibre viewer for non HTML based formats, I use Honeyview for CBZ and CBR, PDF xChange for PDFs, and WinDjView for DJVU.

To not use the calibre viewer for a format, and have it invoke the OS default, uncheck it in the Preferences->Behaviour->Use calibre viewer for: list. The formats I mentioned are unchecked by default.

BR

[calibreian]

Thanks for your response, I have tried 8.5, it happened on this and 8.4, no luck. I would be willing to use alternative software for reading the CBZ’s, I just wanted to figure out why the basic functionality isn’t working. It seems like something in how I have it setup is failing since it is copying new CBZ files every time it fails to open. I have 5 200mb folders in the cache of the same comic book.

[DNSB]

Originally Posted by calibreian

It seems like something in how I have it setup is failing since it is copying new CBZ files every time it fails to open. I have 5 200mb folders in the cache of the same comic book.

Since the calibre viewer does not natively display cbz, cbz or cb7 files, it has to convert them to epub before the viewer can display them. It appears that the conversion pipeline is having issues with your files which is why you are getting the cached files.

What happens if you attempt to convert the file to ePub before displaying it?

[calibreian]

That's what I was thinking as well, DNSB, just can't figure out why. Converting it to an EPUB, it does then open. But adding another different CBR to the library and attempting to open it goes back to producing the same error.

[kovidgoyal]

That's a permission error, almost certainly caused by some software interfering with calibre by opening those files while calibre is processing them, typically antivirus/security/file sync software. reboot in safe mode and see if it works to confirm.

[calibreian]

Thanks Kovid. I tried rebooting in safe mode and one CBR file that had not been able to load did work correctly, though a different file still had the same error show up. I can't seem to find a pattern with which files do and do not work correctly, beyond that the files that don't work end up in the calibre-cache\svrb\s folder, while the working files end up in the calibre-cache\svrb\f folder.

[kovidgoyal]

s is the temp folder in which files are processed f is the final folder into which fully processed data is moved. Any failure will remain in the s folder, successes are moved into the f folder.

[kovidgoyal]

Try using the env var to change the calibre cache directory as described in https://manual.calibre-ebook.com/cus...ment-variables

[calibreian]

Thanks for the suggestion, I did change the cache directory with the environmental variables, both to another folder in C:\ as well as on another drive just to test on E:\. I got the same result:

Traceback (most recent call last):
File "calibre\srv\books.py", line 127, in job_done
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: '\\\\?\\E:\\Calibre Cache Test\\srvb\\s\\kydei6x4' -> '\\\\?\\E:\\Calibre Cache Test\\srvb\\f\\6e6270df89791c3b538c808cdbc9756ef60 d6dd1'

[kovidgoyal]

Out of ideas then, sorry.

[PeterT]

It might be interesting to see what process Windows claims has the file open. Maybe try using either Handle or Process Explorer from SysInternals.

https://learn.microsoft.com/en-us/sy...wnloads/handle

https://learn.microsoft.com/en-us/sy...ocess-explorer

[calibreian]

Appreciate the suggestions, Kovid. Hopefully I'll figure it out or I can just use it with an external CBR reader or convert everything to EPUB. I really like your program though.

And PeterT, I have actually tried Process Explorer which is the GUI version of handle, as well as File Locksmith. As for Process Explorer, I won't pretend to completely understand the data it's providing, but I see two calibre-parallel.exe executables running. I've looked at the handles and everything it provides, everything looks normal (though a bit over my head) but I'm not certain how to track if/what is accessing the CBR files in particular. With PowerLocksmith, I've checked and it says nothing is accessing the files, including when run as administrator.

[PeterT]

So at least its not something like an AV program locking the files...

[JSWolf]

Originally Posted by calibreian

Thanks for the suggestion, I did change the cache directory with the environmental variables, both to another folder in C:\ as well as on another drive just to test on E:\. I got the same result:

Traceback (most recent call last):
File "calibre\srv\books.py", line 127, in job_done
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: '\\\\?\\E:\\Calibre Cache Test\\srvb\\s\\kydei6x4' -> '\\\\?\\E:\\Calibre Cache Test\\srvb\\f\\6e6270df89791c3b538c808cdbc9756ef60 d6dd1'

Here is the way to find out what is using your files.