# (ToolsNet Web App) IIS gives error 500

Cause: IIS returns 500 errors and ToolsNet Web page fails to load.

Solution:

1. Check that .NET Desktop Runtime 8.0 and the ASP.NET Core Runtime 8.0 Hosting Bundle are installed. Do not use version 8.0.19 of the hosting bundle; any other 8.0.x version is acceptable. If installation is missing or components are corrupted, attempt to repair or reinstall them.

2. Refer to Configuring Windows Server 2019 for ToolsNet 8 for IIS setup. In the IIS role features, enable the WebSocket Protocol under Application Development. Make sure all IIS prerequisites from the configuration guide are applied.