It keeps happening with RWG maps. Here is another seed where the trader quest is broken.
@unholyjoe, if you haven't yet, please try this on a Macintosh computer.
My specs are as follows:
iMac (Retina 5K, 27-inch, Late 2015)
3.3 GHz Quad-Core Intel Core i5
16 GB 1600 MHz DDR3
AMD Radeon R9 M395 2 GB