I reinstalled SEV and patched to 1.58 Processed games with out plrs and now they can be loaded again. One turn of cleanning up AI mess for all the changes they made.
I had a 'Incorrect data files' problem when I tried to load a BM1.09PBW game. I found out there was a small change to the mod, and after I downloaded it again it worked ok, so perhaps you have the older BM1.09PBW version like I did which is not compatible with the current one used on PBW.