Could not load library /home/user/.local/share/Steam/steamapps/common/Half-Life/ag/cl_dlls/client.so

[zahirmelian]

i have been having this issue on Linux Mint latest release 22.1 when i try to open the game.

I never had this issue on Windows 10, even if i replace client.so with the latest .so file the error appears again.
I'm not using proton, just the native official Half Life on steam and I have the latest Mesa drivers updated.

[mechanicalground]

that's because your on the 25th anniversary build, you need to revert to the legacy version