Debug Request Could Not Be Processed By the Server Due to Invalid Syntax -
look in %TMP%\Visual Studio Web Debugger.log for clues
directory, create - Creating a directory using ASP.NET 2.0 and VB .NET
Tools → Options → TextEditor → All Languages → Line Numbers check box available under Display section.
port, specify - from here
or, right click the the project in question, go to Property Pages. In the Start options change Start URL.
To check which .NET target framework is installed or available on your system, here are a few useful commands depending on your environment
dotnet --list-sdks
dotnet --list-runtimes
These commands will show you all installed versions of the .NET SDK and runtime, including their target frameworks (e.g., 6.0.100, 7.0.200, etc.).
Tutorial - Step-by-Step ASP.NET Tutorial for Beginners