MCREATOR stuck on RunClient after quitting Minecraft

Basically, I have added a few blocks that act like TnT under certain circumstances. On of them will explode, then strike lightning about 100 times (I know, that is too many, and I am going to change that). My issue arises when I am testing and attempt to close the game. Minecraft will close normally, but Mcreator will get stuck on runClient and I have to force quit the application. In fact, none of the Mcreator GUI will respond. The app says it's responding, but I can't seem to get it to work. This only began when I upgraded to the version 2021.2 and everything before that would work perfect. The other odd thing is when I don't load a world, it will work fine and the game will quit and I can keep modding. I will update this if needed, but for now I have no clue what to do since I can't test my mods without quitting the software then opening it back up.