If you mean this file, mine was always unchecked readonly state, so i dont need to uncheck it at all.I did some research, and this is what I found out:
FPS drawdowns are only in this version. Apparently they added something, but poorly optimized. Some of these problems can be solved by unchecking the "Read only" section in common.rpgsave
Also (I do not know about you), my antivirus deleted one of the files, which also affected the performance. I downloaded the file, launched it, and there were less problems. After I turned on the antivirus, it deleted the already executable file, so it’s better to disable it too at the time of installation and game.
Сommon.rpg save you can find in 'www' folder
And if you deleted some file that might cause lag, which is it and where to find it? Can you give me that file you deleted and redownloaded so i can try it out pls?