What version of BE are you trying to install?
BE 2.5 and above requires Asp.Net 4.5 in order to run.
The error you are getting is a very generic error, it is telling you to turn on remote errors so you can see what the actual error is.
What you can do is zip your wwwroot folder as is.
Very important to Zip, If you just do FTP file by file you are going to get errors.
- It takes much longer
- You can miss files.
Then once you got the zip on your computer, unzip and open in Visual Studio.
You will see the actual error then.