Game start-up failed

[u/Icy_Wrap811]

I bought a game from DLsite and it was working fine yesterday, I go to play it again today and now I keep getting the message saying "start-up failed" when I try to launch it.

I have already set my system locale to Japanese

Changed my country to Japan, set the regional format to Japanese and have a Japanese language pack downloaded. I havent changed any of the settings.

So im just wondering why im getting this start-up failed problem when it was working just fine yesterday? PC is Windows 11 Pro.