TCA tool bar button has disappeared. When zero addon buttons are selected to show, the tic, tac, tow pattern appears, but if TCA is the only addon selected to show on the tool bar, then nothing shows on the tool bar.
Error with build .223 [Error]: MechJeb module MechJebModuleMenu threw an exception in DrawGUI: System.InvalidOperationException: Operation is not valid due to the current state of the object at System.Linq.Enumerable.Single[Type] (IEnumerable`1 source, System.Func`2 predicate, Fallback fallback) [0x00000] in <filename unknown>:0 at System.Linq.Enumerable.SingleOrDefault[Type] (IEnumerable`1 source, System.Func`2 predicate) [0x00000] in <filename unknown>:0 at MuMech.ToolbarTypes.getType (System.String name) [0x00000] in <filename unknown>:0 at MuMech.ToolbarManager.get_Instance () [0x00000] in <filename unknown>:0 at MuMech.ToolbarManager.get_ToolbarAvailable () [0x00000] in <filename unknown>:0 at MuMech.MechJebModuleMenu.SetupMainToolbarButton () [0x00000] in <filename unknown>:0 at MuMech.MechJebModuleMenu.SetupToolBarButtons () [0x00000] in <filename unknown>:0 at MuMech.MechJebModuleMenu.DrawGUI (Boolean inEditor) [0x00000] in <filename unknown>:0 at MuMech.MechJebCore.OnGUI () [0x00000] in <filename unknown>:0