Where is the "wbb5v1gn.newcfg" coming from? My guess is that this is a temporary file that Properties.Settings produces on the fly, but somehow it is getting blocked during a race condition. %AppData%\Local\Black_Tree_Gaming\NexusClient.exe_Url_gain1zdhkpbyw2jzilftlyqygdtwzisk\0.65.6.0\wbb5v1gn.newcfg
%AppData%\Local\Black_Tree_Gaming\NexusClient.exe_Url_vh54beimn2q1o1erkxensurtymrgxq20\0.65.7.0\nfigīut all the users seems to be reporting something like this: When I run the program myself I get the following (using short hand): This is just today mind I am looking at this bug and as you suggested it is hard to reproduce. alongside the occational 'NMM doesn't show up'. Well, I'm getting 'just starting and crashes' problem.