My game was crashing as well (going either right or left right from the hangar) and I could not find anything about it other than issues in different parts of Manaan. It also had nothing to do with grass or the like.
In the end what thankfully helped me was to set Shadows=1 to Shadows=0 in the ini file. No more crashes in Manaan!
To be on the safe side, disable shadows every time during your stay on Manaan. That can be annoying but I could not find a permanent solution.
Hope this helps somebody who finds the thread!
Post edited September 23, 2021 by MadJak91