try the event ''on inventory click''

 

Don’t use format slot, use skQuery’s GUI manager.

 

I mean both are better than format slot..

 

Oh I thought it was Skript’s built in GUI manager.

 

So. Another block, that opens another gui? Like this?

Code (Skript):

1. command /menu:
2.       trigger:
3.             open virtual chest inventory with size 6 with name "&e&lCustom Menu" to player
4.             format gui slot 0 of player with a grass with name "&b&lMinigameHub" to close then run console command "mvtp %player% MinigameHub"
5.             #Now is the part you don't know:
6.             format gui slot 1 of player with a bedrock with name "&cSome Other Gui" to close then run player command "agui"
7.  
8. command /agui:
9.       trigger:
10.             #same here, virtual chest inventory, format gui slot,...

You can change the "bedrock" to another block, the name, the command. This is works only with Tuske, I am using TuSKe 1.8.3-PikachuPatch-v3
And you can add other blocks with format gui slot 2,3,4... of player with something with name "something"
And now, if this block opens another gui, you don't need to write "to close then.." only "to run player/console command"
I hope this is what you want