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MCC Linux Desync
Take the file ucrtbase.dll from a Windows install at C:/Windows/System32/ AND C:/Windows/SysWOW64 then place them in the folders for Steams Proton (case sensitive) :
/home/user/.steam/steam/steamapps/compatdata/976730/pfx/drive_c/windows/system32
/home/user/.steam/steam/steamapps/compatdata/976730/pfx/drive_c/windows/syswow64