What happens is that I'm working on a web application that includes DevExpress in version 15.1.7.0 and I get an error when compiling:
Compiler error message: BC30009: Reference is required to the assembly 'DevExpress.Data.v15.1, Version = 15.1.7.0, Culture = neutral, PublicKeyToken = b88d1754d700e49a 'containing the Implemented interface 'DevExpress.Utils.IAssignableCollection'. Add one to the project.
But I have already added the reference to my project.