arrrggh, too late. I found a bug. If you want to insert a "Raise UI request" to your script, the combobox shows one entry with all requests. If you want to delete it again, you get a bug.
EDIT: another one. If you add a picture to a room you get the message (when running the game):
Error running script: Error compiling expression 'game.useframe': RootExpressionElement: Cannot convert type 'Object' to expression result of 'Boolean'
Same is coming when calling thenew request SetPanelContents