Thank you for the report.
I have bisected the issue to start with commit https://github.com/doitsujin/dxvk/commit/4b0795359f470804a53fa3b7852e47bc9b72633d. Specifically the d3d9.ffUbershaderFS part.
Edit: Renderdoc capture sims2-no-shadows-renderdoc.zip
Thank you! Looking forward to the fix. ~I was able to set this variable in dxvk.conf to false as a workaround and I got shadows back~ Never mind it didn't work on the latest Proton versions. Waiting for the fix
See PR above, I'm unable to test the actual game but based on the renderdoc capture it should fix the root cause.
proton experimentalx1 2026-05
In the Sims 2 Legacy Collection and even on Ultimate Collection on DXVK 2.7.1, there's no shadows in Sims and in outdoor objects like the mailbox and trees using Proton Experimental and Proton 11. In Proton 10 and GE-Proton-10-15 (the last versions on DXVK 2.7), the shadows work as intended.
Software information
The Sims 2 Legacy Collection (Steam version), but applies to Ultimate Collection as well.
System information
Apitrace file(s)
None - can't seem to get one without the game crashing
Log files
steam-3314070.log