Did you download this to or as a standalone game ? What files are inside the .rar (e.g., .exe , .json , .obj )? Are you getting a specific error when you try to run it?
: Use a tool like 7-Zip or WinRAR to extract the contents of the .rar file to a folder of your choice. Workshop-Simulator.rar
: If you load a mod in TTS and see "white boxes," it means the asset links in the .json file are broken or the files aren't in the correct Mods/Images folder. To help you better, could you tell me: Did you download this to or as a standalone game