I upgraded to 3.5.4+ but mu problems started before. I had to restore my files during a mistake with migration. After restoring my sound files and photos didn't load. The sound files said the media player could not load and the photos first appeared as a rainbow of colours and then disappeared. This has happened in both databases: the one prior to migration and the one after. So, with the database prior to migration I thought that an upgrade might solve the problem. The upgrade went ahead as planned but the problem still existed. Both restore were done with unproblematic backups three months apart with no problem showing up when I was using Moodle. I can reupload the picture and audio files and they work without a problem. The Global php version is 7.1 (in case this is causing a problem). Can anyone help.