Unable to find plugin in the plugin search path: SpecRun` when saving / generating feature files

SpecFlow searches for plugins in the NuGet packages folder. This is detected relative to the reference to TechTalk.SpecFlow.dll. If this DLL is not loaded from the NuGet folder, the plugins will not be found.

A common problem is that the NuGet folder is not yet ready (e.g. not restored) when opening the solution, but TechTalk.SpecFlow.dll in located in the bin\Debug folder of the project. In this case, Visual Studio may load the assembly from the bin\Debug folder instead of waiting for the NuGet folder to be properly restored. Once this has happened, Visual Studio remembers that it loaded the assembly from bin\Debug, so reopening the solution may not solve this issue. The best way to fix this issue is as follows:

1. Make sure the NuGet folders are properly restored.
2. Close Visual Studio.
3. Delete the bin\Debug folder from your project(s).
4. Reopen your solution in Visual Studio.