I am using the latest version of Rollbar.NET in an ASP .NET MVC application that is hosted on IIS and uses .NET Framework 4.8. However, the RollbarConfigurationLoader (its static constructor) uses RuntimeEnvironmentUtility.GetSdkRuntimeLocationPath() to determine the location where the DLLs are to dynamically load the configuration loader module (e.g. Rollbar.App.Config).

However, in the IIS world the actual DLLs are located in a bin subdirectory and not in the work directory (where the web.config is). Maybe when searching for the configuration loader modules, both the sdk runtime location path and its bin subfolder should be checked. Or one could check the location of the Rollbar.DLL and use that as a base path to probe for the additional modules.

You can reproduce the issue when you create a new ASP.NET Web Application (.NET Framework) project and choose MVC.

In order to workaround this issue, I have to copy the DLL out of the bin folder into the working directory. Thats kinda ugly though.