Per paradox employee:



AndrewT (Paradox Interactive)



Mar 22, 05:11 CET



I am sorry but we are not going to be able to provide either of those things.



We only support and test games with the current Steam client version. We cannot expend support and developer resources retrofitting new game versions to run under old Steam versions. In this case presumably Steam changed their APIs in the new client and HBS changed the game to detect to those APIs accordingly, so it does not see the obsolete APIs in the old client ("InvalidOperationException").



I don't believe there is anything you can manually edit to change that. It would be hard-coded in the game, not in a .json file or something like that.



Please pay close attention to "HBS changed the game to detect to those APIs accordingly" as the old Steam UI worked just fine until this patch and all other games work just fine as well. The addition of the new API monitoring code breaks the game. As this code is irrelevant, it is nothing but telemetry.



EDIT: Game breaks via altered "black screen of death". There are menu options, but no background image and game is unable to start. You can access options menu.