Hello Eric.
That issue caused on any transparent material, with any of attributes. Empty, clear material works fine, but when I change material type to any type which use Opacity node, UE4 is collapsing.
About Map issue: I dont want to open 4.8.3 on 4.3, I just trying to open 4.9.2 on 4.9.2 after simple restart my computer, and this error was corrupt on 4.8.3 also. So, I saw that this issue starting only after Epic Game posted new engine version. Im sorry about “whats wrong with u”, but I`m really try to understand whats going on