Getting Aldiko to return library books

[MingSnz]

Hi

I have Aldiko running with Android 5.1.1. Tried other readers but this works best for me. I believe I downloaded it, as opposed to it being factory installed.

It was working well both with downloading and returning library books. Just long pressed the book, tapped "return to library" and done.

But something has changed and I get "cannot return book" which isn't very helpful. I tried clearing the cache and uninstalling the app but when reinstalled all the books reappear and I still can't return them.

Any suggestions gratefully received.