Closing, there is no bug here. The free edition does count groups, variables etc. as events towards the 100 limit, even though the editor only numbers event blocks. Please also follow the bug report guidelines when reporting bugs - the original post includes 70-80 events, which is too many to prove it's a C2 bug and not just a mistake in your own events, which is why we ask for absolutely bare minimum reproduction .capx files only.
Ok, I just want to ask whether it may be bug to be through some events that logically has not lead to bug. Because I make the problematic event on separate layouts, and there is no bug.