So there's this really annoying bug in 1.9.0 whice happens when I make a custom GUI and then make/edit a element and after that it shows up this like page thing whice says that there's an error in my workspace and says that the element that is causeing this error is the GUI and then there's like 3 buttons at the bottom whice let me do something about it (to either show me the compilte log or something or to delete the GUI or to do nothing) and I have tried EVERYTHING to stop it from showing up I even tried exporting the mod with the error (But the gui does not work in the mod) Pleas help!!!!
Did you bind the GUI to the block? It could be that the block you bound the GUI to does not have inventory enabled.
I suggest you to check our wiki page on how to make GUIs with slots: https://mcreator.net/wiki/making-guis-slots If your GUI does not work after watching the tutorial, you might want to check our example workspace and build from there: https://mcreator.net/modification/42649/fusion-table-procedure-demo
If this does not help, reply back and I will further assist you.