Hello @lucaspeed72, this is apt telling you that your 32 bit mesa install is incomplete. This is a distro packaging issue, not a Steam client issue. Linux Mint inherits Debian's multi-arch requirement that all architecture variants of a package must have exactly the same version. Apt also strongly dislikes downgrading packages to resolve conflicts.

I'd start by checking what versions of libllvm19 are available with something like apt policy libllvm19 libllvm19:i386 and asking apt to install both the 32 bit and 64 bit variant of that package at the same time with something like sudo apt install libllvm19=<version from apt policy> libllvm19:i386=<same version from apt policy>. NOTE: if at any point during troubleshooting, if apt asks your permission to remove a bunch of packages, do not let it.

If apt shows additional conflicts, then repeat the process of checking what versions are are available for both 32 bit and 64 bit until you find which package is mismatched in your distro's repositories.