I restored Moodle 3.4 and upgraded it to Moodle 3.5. After that I almost can not play media files. The error message is "The media could not be loaded, either because the server or network failed or because the format is not supported". Initially I thought that it was spaces in the filename that caused the error, I uploaded a mp4 file without spaces, and it worked well. But after restoring again I can play the file with the spaces, but not other files with spaces in the filename.
In addition H5P videos show nothing at all, not even an error message.