Noticed this 19x in someone's logs before they crashed.

268364 [LOG 20:46:55.419] [KSPCF:MemoryLeaks] A destroyed TarsierSpaceTech:TSTMstStgs instance is owning a OnGameSettingsApplied GameEvents callback. No action has been taken, but unless this mod is relying on this pattern, this is likely a memory leak.

This line should be removing the event handler, not adding another one :p