I had a similar issue earlier this year. The problem ended up being a failing rear drive unit, which Tesla replaced for about $3,700. My error was accompanied by reduced power and no regen.
Other possible points of failure causing a loss of high voltage isolation include the PTC cabin heater if your car doesn't have a heat pump, the air conditioning compressor, and the battery pack itself. The most likely culprits are the cabin heater and air conditioning compressor. I think one of these is your issue since you didn't mention reduced power and regen.
Schedule a service appointment and Tesla will take care of you. If the high voltage isolation degrades to a certain point, the car will not let you drive. How long you have depends on exactly what's wrong. On the plus side, it won't shut down on you if you're already driving, so you shouldn't have any issues driving to the service center.