TestFlight - Accidentally disabled, how to enable again?

Title says it all - I must have accidentally disabled TestFlight and now even the button on the toolbar is gone so I can't enable it again. Does someone know a way to enable it again? If I start a new career it's there but not in my current run.

[Edit] Figured it out myself: In the save file there's a SCENARIO node "name = TestFlightManagerScenario" and there's also a line "saveData = settingsenabled:False," - deleted that line and TestFlight's back again.