Such an error means one of the following:
- the project referneces are not actually correct for referencing the assembly from the GAC
- OR, the assembly is not properly registered in the GAC
This blog post will show you how to examine both: http://blogs.telerik.com/aspnet-ajax/posts/13-09-19/working-with-assemblies-in-the-global-assembly-cache.
Our assemblies are not special in any way and the standard processes for referencing them from the GAC apply.
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