Your system information

• Steam client version (build number or date): 1573176642
• Distribution (e.g. Ubuntu): solus 4.0 64-bit
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Not yet, I'll let you know

szm@solus ~ $ steam
Running Steam on solus 4.0 64-bit
STEAM_RUNTIME is disabled by the user
Error: You are missing the following 32-bit libraries, and Steam may not run:
libva.so.2
libva.so.2
libva-x11.so.2
/home/szm/.local/share/Steam/ubuntu12_32/steam
Installing breakpad exception handler for appid(steam)/version(1573176642)
Installing breakpad exception handler for appid(steam)/version(1573176642)
Installing breakpad exception handler for appid(steam)/version(1573176642)
Failed to load steamui.so - dlerror(): libva.so.2: cannot open shared object file: No such file or directory
Installing breakpad exception handler for appid(steam)/version(1573176642)
Installing breakpad exception handler for appid(steam)/version(1573176642)
[2019-11-09 15:07:34] Startup - updater built Nov  7 2019 23:57:30
[2019-11-09 15:07:34] Opted in to client beta 'publicbeta' via beta file
You are in the 'publicbeta' client beta.
Looks like steam didn't shutdown cleanly, scheduling immediate update check
[2019-11-09 15:07:34] Checking for update on startup
[2019-11-09 15:07:34] Checking for available updates...
[2019-11-09 15:07:34] Downloading manifest: client-download.steampowered.com/client/steam_client_publicbeta_ubuntu12
[2019-11-09 15:07:35] Download skipped by HTTP 304 Not Modified
[2019-11-09 15:07:35] Nothing to do
[2019-11-09 15:07:35] Verifying installation...
[2019-11-09 15:07:35] Performing checksum verification of executable files
[2019-11-09 15:07:35] Verification complete
[2019-11-09 15:07:38] Shutdown

Steps for reproducing this issue:

Literally I have no idea. It happened suddenly.