Undeletable epub file


I have encountered the following issue.

I copy an epub file (from an archive) onto one of my drives (inside of several subfolders). Then I copy the file from this folder to another folder on another drive.

Afterwards I cannot delete any of those two epub files because there seems to be a lock on those. When I quit Dopus and then try to delete with explorer deletion works fine.

Looks like Dopus is inspecting the file for some reason and then forgets to remove the lock.

Alternativeley this might be due to a very long filename. Not sure about this.

Looking forward to a fix.

Thanks in advance

It probably won't be Opus itself locking the file. (There is no code in Opus itself that knows what an epub file even is.)

It will likely be a third-party component which is probably being called on to make a thumbnail or display the file in the viewer. Those run inside the process which calls on them, so if it's Opus then the lock will be in dopus.exe; if Explorer did the same the lock would be in explorer.exe, but in both cases some other DLL is ultimately what left the file locked.

You can use ShellExView (get the 64-bit version) to view which shell extensions are installed on your system. It'll probably be one that is part of software that handles epub files.

(It's also possible for other things like antivirus to lock files, although less likely; that usually blocks files from being opened rather than locking them once they are open. It can also happen due to bugs in Opus, but that's fairly rare and would likely have a lot of reports on the forum if it was happening.)

Hi Leo,

Thanks for the quick reply. My last thought in my report was true. It seems that there is no lock but the deletion fails because the file name is too long. Is this problem known?


The Windows Recycle Bin API has problems with some filename lengths, which we can't do much about. (It says it succeeds but doesn't delete the file sometimes, for very long path lengths.) That affects File Explorer as well, though, so I don't know if it's applicable here.

If you delete without using the Recycle Bin (e.g. hold Shift when deleting, or turn off using the Recycle Bin in Preferences), Opus does the deletion itself and will work with any path length.