sorry to keep bothering you about it. 😅 but yeah. It said that while I was trying to download the mod through the link you sent, is it because since the mod says Gacha Star it could be interfering with the newest one since that one is also named Gacha Star?
Viewing post in Gacha Mod Porting page comments
i fixed it ^^
https://www.mediafire.com/file/h775k54gsr3z2jc/Gacha+Star_signed.apk/file
Basically added an extra code to the package name which was 2.1 and messed up how the package kinda says invalid (-m-")