I just began playing again, and have brown boxes too. The twist is that I'm playing the Origin version, and it's still using games I saved in 2015. I did download a new version from EA before they became Origin which was completely glitchy, probably because I had files and another plugins folder for the old version buried in a drive. I'm happy to be playing it on Windows ten. I'm not sure which plugins folder the Origin version is using, but I'm going to play around with it.
If this has been solved elsewhere, apologies and thank you.