IGSO is still being run.
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (50): Unable to find object: '' attempting to call function 'getExtent'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (54): Unable to find object: '' attempting to call function 'extend'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (58): Unable to find object: '' attempting to call function 'getPosition'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (61): Unable to find object: '' attempting to call function 'getExtent'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (64): Unable to find object: '' attempting to call function 'resize'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (58): Unable to find object: '' attempting to call function 'getPosition'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (61): Unable to find object: '' attempting to call function 'getExtent'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (64): Unable to find object: '' attempting to call function 'resize'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (58): Unable to find object: '' attempting to call function 'getPosition'
Add-Ons/Gamemode_TeamDeathmatch/MinigameGUI.cs (61): Unable to find object: '' attempting to call function 'getExtent'
It seems that the minigame GUI isn't being created or something has gone wrong. Try entirely removing IGSO, it may be editing the GUI for v11 even though it's changed in v12.