64 bit Steam game trying to load 32 bit library in 21.04

[Daniel]

I'm having some troubles getting a 64 bit Steam game (Cities: Skylines) to work in Kubuntu 21.04. The game worked under both 20.04 and 20.10 for me. The error from the games log file is the following:

ERROR: ld.so: object '/home/daniel/.steam/debian-installation/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.

Cities is a 64 bit game so I'm pretty sure that trying to load from the ubuntu12_32 directory is the issue when the same files are available from the ubuntu12_64 directory. Has something been changed from 20,10 to 21.04 that can have caused the error? If so, are there any environment variables that I can set that will make the game load the gameoverlayrenderer.so file from the correct directory? What I have found seems to suggest that the 64 bit library should load anyway, but since the game is refusing to load it seems that it doesn't.

Thank you!

[claydoh]

It would more likely be a Steam issue, BUT:

ERROR: ld.so: object '/home/daniel/.steam/debian-installation/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.

This is not truly an error message, or rather it is not a fatal one, as steam tries to load both 32 bit and 64 bit libraries for some things, and the one that is not appropriate is ignored, as the message says. This is quite normal. So different errors in the log may be more useful.

[Daniel]

These are the errors in the log:

ERROR: ld.so: object '/home/daniel/.steam/debian-installation/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Setting breakpad minidump AppID = 255710
malloc(): invalid size (unsorted)

The AppID is correct, which leaves the malloc() error as the possible cause?

Edit: forgot to add that is was previously working under 20.10.