After a recent steam update, warband will no longer launch (while the configurator will work fine). The issue lies with how to game has been set up, as it's calling the binary (mb_warband_linux) directly instead of the bash script (mb_linux.sh). This has for effect that the binary is unable to find a library:
This issue is partially being discussed on the steam runtime bug tracker: https://github.com/ValveSoftware/steam-runtime/issues/301
Discussed in the linked thread, the script mb_linux.sh also has one major issue. Mainly it overrides the LD_LIBRARY_PATH variable instead of appending to it.
MountBlade Warband/mb_warband_linux: error while loading shared libraries: libfmodex64.so: cannot open shared object file: No such file or directory
This issue is partially being discussed on the steam runtime bug tracker: https://github.com/ValveSoftware/steam-runtime/issues/301
Discussed in the linked thread, the script mb_linux.sh also has one major issue. Mainly it overrides the LD_LIBRARY_PATH variable instead of appending to it.