Unable to compile application

Problem

You get this error when building your application in Iron Speed Designer with the Visual Basic .NET compiler:

Unable to compile application...

Solution

Check to see if your solution file (SLN) contains a VBPROJ file that includes multiple AssemblyInfo.vb files.  If a VBPROJ does include multiple AssemblyInfo.vb files, you must exclude (or move, delete, etc.) all but one of them from the project to avoid the compilation error.

This can also happen if you are using Crystal Reports in a Restful application. Crystal Reports requires a connection to the database for pulling the data. However a Restful Application uses a Web API to do so and is not compatible with Crystal Reports.