The issue you're describing seems to be related to dependencies introduced in the new version (150.1620.0) of the Microsoft Reporting Services ReportViewerControl Winforms nuget package. Here are some steps that could help you address this problem: Specify Copy Local: Ensure that the DLLs for reporting services are being copied to the output directory. In Visual Studio, go to Solution Explorer, find the reference to your DLL, right-click on it and select Properties. There's a property called "Copy Local". Make sure it's set to True. ClickOnce Application Files: Open the properties of your project, go to the Publish tab, click on "Application Files...". In the window that opens, make sure all necessary DLLs have their Publish Status set to "Include". Manually Add DLLs: If the above solutions don't work, as a last resort, you can manually add the DLLs to your published application folder after publishing.
Remember, the standalone .exe file requires all necessary DLL files to be in the same directory so it can run correctly. If one or more DLLs are missing, it will fail to run.