Thank you for your feedback and taking the time to reach out to us.
According to this error, maybe you could refer to this similar thread, and check if your IIS was configured to use another project. Or you could run cmd in administrator mode, and run this command:
iisreset to reset your IIS.
In addition, please check if there are some modifications you missed in project properties.
Note: please make sure if the "App URL" contains an application name.
If it doesn't work, since VS calls IIS express or IIS to debug mvc application, we also suggest you could post this question in IIS forum, the community members would provide better support about it.