In Steam, go to Settings > Downloads > Clear Download Cache . You will need to log back in afterward.
If you're using C# with , the flow is:
While there is no single official function called SteamAPI_Init_download , this phrase typically refers to the initialization process required before an application can interact with the Steam Workshop or download specific content (DLC, items, or updates) via the Steamworks API. steam api init download
The application must run under the same as Steam. Troubleshooting Initialization Failures In Steam, go to Settings > Downloads > Clear Download Cache