I just had this issue as well. I just finished the second Victoria mission and was about to click the CTR button in the Searcher menu when the game crashed with the following:
Engine error
Index out of range (-4 >= 256)
Class: 'Vehicle_WidgetHandler'
Function: 'SetWidgetDefaultColor'
Stack trace:
scripts/Entities/Vehicle/WidgetHanlder.h:108
scripts/Entities/Controllers/Modules/VehicleTabs.h:518