When I try to compile any document in LyX, I get this message:
Package inputenc Error: Invalid UTF-8 byte 179
Nothing I found on the web is working. Neither changing the preamble nor setting the LyX itself. I also tried to change the coding in the external program. It turned out that I was left with dozens of files that are useless because I can not compile either old or new ones.
How to force LyX to create a file that can be compiled? The file is to be in Polish.