After installing the Expedition DLC, I found two issues, both of which persist after disabling the DLC.

1. After the intro for a new game, the screen turns black and never loads
2. I cannot save any of my old games

I've tried several different solutions, including updating DX9 (per support's advice), adding Underrail to my Antivirus exceptions, and running as an administrator.

I'm curious if anyone else has seen these issues, and has any advice.

Same here. Just bought it, won't run.

Followup:
I had to set it back to default video to run.
Windowed, basic resolution. vsync etc...

I have a 34" Alienware and the game would not start after character creation.
Just sat in the first room. Not sure yet if its the resolution, 120hz, etc... but setting back to normal just to get started works.

Do you happen to have a high res or 21:9 display? Thats what mine is. It apparently hates that.

Followup 2:
Fullscreen, vsync on but default resolution works.
Seems for me the core issue is running 3440x1440.
So keep it the default resolution but fullscreen and you should be fine.