My car has been intermittently playing the brake / indicator failure warning game for the last 6 months, but the bulbs were actually functioning fine. Then in the last 2 weeks, the warnings become permanent and the lights had actually stopped working this time.
Fixed it this weekend. Unfortunately the easy fix, 1 pin swap out, wasn’t viable as the remains of the disintegrated pin from the bulb holder was stuck in the connector, meaning it couldn’t be released from the plastic plug body. Maybe if you catch it when the error is intermittent, you’d get away with just replacing the bulb holder and 1 pin in the plug.
Mine ended up needing the new plug body, re-used the other 3 original female pins with 1 new pin from the repair kit and the new bulb holder.