From one day to another one of my Filemaker files (hosted on FMS15) had two of the fonts replaced with a font I have never heard about before, Sergue Print, and the other was replaced with Arial and also Bold.
It happened on both text and fields, and on all layouts with those fonts. It is definitely related to the files, because the error is visible in all clients and both Mac and Windows. (on Mac the new fonts are different though).
It is not related to the .TMP font error which is a known FM bug. I have seen that error also, and that is related to a client and can be fixed.
I have tried to recover the file, but no errors found, and the problem does not go away.
I have also loaded a backup to compare, and the errors is not present in the backup.
But I would like to find a solution, in which I can avoid to correct each layout manually or to import all data and scripts back into a backup.