Convert ASPR From v6.2 To v10.5

I have a number of web pages built with ASPRunner v6.2 that I would like to convert to v10.5 and have the pages look as they did in the older version including menus and custom views.
I tried just opening them in the new version and rebuilding but when trying to view in browser I get:

HTTP Error 500.24 - Internal Server Error
An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.

Any ideas would be appreciated!