Reading is hard! Well, WTCC isn't exactly brimming with car-models. Macau is one of the heavier tracks if I recall correctly though... 64-bit can't come soon enough.
If I remember good it was a server with only WTCC (16' and 17') and there was 2 players already connected. I entered this server several times and this is the only time it crashed. But if you look my recent reports, I already reported 3 crashes with dump since last patch, it's more than usually.
Yeah, wondering what the cause is. It's not your hardware, I'm pretty sure of that. Some changes were made to MP to reduce join lag but that shouldn't cause this error.