After updating to 1.08 my save file disappeared. I looked in where the saves normally go in C:\Users\XXX\Documents\The Witcher 3 and also where the game was installed in C:\Program Files (x86)\GalaxyClient\Games\The Witcher 3 Wild Hunt. I am using the galaxy client. Anyone else with this issue or tips for a possible solution?

Try a recovery tool to restore the missing files. I can't recommend you one because I never have to use one before. I backup my system drive once a month so there is no need for me.