Hello @brandonegbert, please add PROTON_LOG=1 %command% to the game's launch options and drag and drop the generated $HOME/steam-$APPID.log into the comment box.
My mistake, thought I had it attached.
steam-1198740.log
If error message is accurate it's likely about D3DX11CreateTextureFromMemory.
PROTON_LOG=1x1 2020-01
Compatibility Report
System Information
I confirm:
Symptoms
Fails to launch with "Error opening data\default\default_gradient.dds". Requested that I send a bug report which I did but was sure to note that it was via Proton on Linux.
Reproduction
Launch the game