Can DOpus show an appropriate error message if a file operation is attempted on a file with a path that's longer than what is supported by the file system? Currently DOpus 12.6 fails silently when deleting on 64-bit Win 8.1.
I'm assuming you are using the Recycle Bin to delete the files.
If so, it is not Opus that is failing, but the Recycle Bin. If you do a delete without using the Recycle Bin, it can handle arbitrary path lengths.
The Windows Recycle Bin API does not indicate failures properly, and has some OS-level bugs with certain path lengths, so we cannot always detect problems it causes when it is used. (The Recycle Bin is supposed to ask if you want to delete files with paths that are too long directly, but it fails to do so in some situations. Bypassing the Recycle Bin entirely solves the problem.)
I'm pressing the Del key with a file highlighted in a lister to send the file to the Recycle Bin. Doing the same in Windows Explorer results in a dialog box asking if I want to permanently delete the file and then a "source path too long" error when Yes is clicked. It's not a big deal - just confusing when you've selected a bunch of files across multiple folders and you don't know why deletion is failing.
The error message you see in Explorer will also be shown in Opus, most of the time (the same is true in Explorer).
That message comes from Windows itself (from the Recycle Bin API), not Opus or Explorer.
I just did a quick test in Opus and saw this:
Opus is configured like this:
(If the command on the Delete button has been edited to add QUIET or FORCE or similar, that could suppress the extra confirmations.)
You may be running into a bug in the Recycle Bin API where it silently fails on paths of a certain length, and does not tell you via an error message, nor tell the program that asked it to delete things. There are situations where the Recycle Bin will say it succeeded when it actually did nothing. From memory, it is caused by paths which are exactly a certain length (maybe 255 or 256 characters); longer paths trigger the confirmation message & bypass the bin, and shorter paths work, but paths of a particular length silently fail, due to bugs in Windows.