Gui keeps crashing in game 2025.2 Forge

I'm trying to make a GUI for my first mod. I've got it all set up, including a procedure to show and hide the GUI when the key G is pressed, but when I went to test it out, pressing the G key would completely crash Minecraft. I heard it could be a client/server-side issue, so I made it run on the server, which stopped it from crashing. However, it's still not showing. I'm no longer sure what the issue is, as I've never worked with MCreator before. I don't have any GUI slots; it's just text and buttons.