Cannot open PDF files

[larkahn]

I've gotten various error messages when trying to open PDF files through Calibre Companion. I have various PDF readers and the result is the same no matter which one I choose after selecting Read inside CC, e.g. the file doesn't exist, it's corrupt, locked whatever. However, if I use a file manager to navigate to these PDFs, there is no problem opening the files. I have a Samsung Galaxy A31 phone with Android 11.

I have a Samsung Galaxy Tab S6 Lite tablet with Android 11 and there are no problems. Therefore, I assume that this is not an Android problem.

One error message suggested shortening the file name. That did nothing. I tried changing the settings on where the ebooks are stored and got a message that the PDF files couldn't be tranfered.

I deleted all of the ebooks and just tried to transfer 1 or 2 wirelessly from my computer. I still could not open the files through CC.

Finally, I Uninstalled CC from my phone and reinstalled it, and transferred a few books. The problem disappeared.

This makes me wonder if the problem is some kind of CC file that got corrupted. Since I don't know what the file was, if it was the main app file itself, or if I could even access whatever file it was, Uninstalling and reinstalling was the only way for me to solve the problem, and it did fix the situation.