Close RT, delete your cache and config folders, re-download RT 5.4 from RawTherapee - Downloads and see if that helps.
Yes it did!
Yes there is an asterisk in the file path. This has earlier been a problem, I couldn’t open files at all. But now, files do open, so I had not exspected it would cause problems later in the process. For now, I moved the raw file to the Desktop, and that worked. Both the direct single saving and the queue.
Except that the name field in the top of the Queue window is clipped. I report on that together with other clippings in the thread
Some problems with RT 5.3 and 5.4
Thank you for your help!