Another strange thing is that when you create a group indicating a particular condition, the group is created out of the condition, the group is created above the condition is not created within it.
The event is created correctly within the condition (pressing key B) but the group is created outside the group, the group is created above the condition.
There you are just missusing C2. If you want to create the group as sub-event of the event "Else/Var=4" and before the blank sub-event, strictly select the blank sub-event, not the top-level event.
This is another strange thing, I do not know if it's a bug or something I do not understand the functioning of C2.
If the "Group 2" group is enabled the condition "Else var = 4" is not executed when the global variable "var" has the value 4.
For run the condition when "var" is = 4, then you must disable the "Group 2" group.
https://dl.dropboxusercontent.com/u/60803633/testGroup2.capx
ELSE is meant to execute only when the event previously to it hasn't executed.
Groups are considered events (hence why they count into the total number of events of the project). So when running through your "Group2" empty group, else considers the previous event has executed, and so won't execute the current event.