Hi TF
I am afraid SH5 is broken and Steam does not support this essential application details found below.
If you are new to SH5 look > > HERE << STEAM is not compatible with the essential application TDW’s Generic File Patcher
Steam Conversion Installation Instructions for SH5 Updated Version
Highly Recommended SH5 > The Wolves Of Steel Mega Mod > Includes KSDCommander And Working Enigma M4 Machine
Any mods can be used with Steam.
Peter