static variable initial value must be a literal expression

I am using version 4.8 with the preset found here:  www.reddit.com/r/totalwar/comments/jjmrh...edieval_total_war_2/
created specifically with that version.

I enabled performance mode but when I compile there are several tabs that do not compile because of the error: static variable initial value must be a literal expression
How can I do this? It seems strange to me that to all the other forum users (in the link above) it works