I bought the Steam version of the game a couple weeks ago, having owned the Battlefront version earlier, and it's mostly been working fine, but now I ran into the same problem as apparently some others have had years ago. With me it came playing as the Axis, and trying to deploy a new Japan garrison unit.
The problem persist in different saved games (atleast the ones where that unit has already been purchased in the earlier turn), so even if I run the end turn again from the previous turn, it gives the same error on the next turn with the same purchased unit: Error: FAILED(draw_unit_layer_to_buffer), and then crashes to desktop. Game version in main menu is v1.10.00 (Steam version).
I didn't originally have any mods installed when this happened, and after I've tried changing in-game graphic resolution, enabling and disabling a few in-game graphic mods (Iron_Cross_Mod_v4-4, SIPRES NATO Counter Mod), verifying integrity of game files in Steam's game properties, turning off Steam cloud saves, deleting the whole game settings directory (C:\users\<user>\documents\My Games\Strategic Command WWII - World At War), rebooting, disabling 3D models, uninstalling and reinstalling etc, but nothing I can think of helps.
Is there a fix for this I haven't found, should I send my savegame files and dxdiag info (+something else?) to some support email address, or what's the procedure on this?