Hello. I keep getting this error as well. I didn't paid attention to it as I could play the game, as my files seem to be save "in the cloud" locally on my hdd. But when hdd become unaccesible and installed Steam on another machine I noticed that there were no saves there, in the 'real' online cloud on Steam. Oh, after writing this I noticed that the thread is for FM23 and my issue is for FM24 - however, as seen below no FM23 saves in my cloud either.
Thanks