This error occured when you run Umbraco. To solve this error, follow below steps.

To Go to IIS. Write inetmgr in run command (Window + r)

Go to IIS Default Web Site Properties -> Home Directory -> Local Path.
Remove "\" character at the end of the directory. It should be C:\Inetpub\wwwroot ( IIS will automatically add \ at last of this (C:\Inetpub\wwwroot\)

You can check Default Web Site Properties -> ASP.NET -> File Location for actual setting information

See below image