I've spent ages on this. It's not doing any harm, just amazingly annoying after a year or so!
Start Log Viewer in the usual way.
It displays a pale yellow panel saying "Could not open the following files" followed by a list (now!) of 4 files. None of these exist in the log directories - I long ago deleted the files, generally misnamed ones when I was initially setting up - but I cannot find where the names are specified. I've searched online, searched the filesystem and home...
Any idea where the list is maintained and/or how I can persuade the viewer to forget them, please?