I uninstalled Pleco to install the version before 3.2.56 from Pleco.com, but the apk-file there is from Dec 27, so I can only tell you what I remember.
I normally work with several .txt-files which I open in the Reader. Therefore with File Reader/List Recent Files I get a list of the files I recently opened, with File Reader/Reopen Last File Pleco reopens the file that was open the last time I used the Reader. As Pleco has no built-in editor for the Reader, I switch to an external editor to change the .txt-files, then switch back to Pleco to open the changed file in the File Reader.
Before 3.2.56 I needed the following steps after switching back to Pleco:
File Reader/Reopen Last File - done! or
File Reader/List Recent Files/tap on the filename - done!
Now with Pleco 3.2.56 from Dec 27 I need the following steps:
File Reader/Reopen Last File and get the messages
"Could not open file"
"Sorry, this file could not be opened"
As you will later see these messages are wrong, as Pleco is indeed able to open the file, but not at this point.
As I know that this will happen in 3.2.56 I can of course immediately take the following steps instead:
File Reader/Open New File/Select the file in an explorer-like GUI/ and get the messages
"Document Modified"
"This document appears to have been modified since the last time you opened it - would you like to keep your previous bookmarks or discard them?"
I tap on Discard. Pleco asks to select the Text Encoding, I tap on UTF-8. Pleco opens the file, proving that the message from above (Could not open file) is wrong.
If there should be an old version before 3.2.56 I do not mind testing to verify my memory.