In VS2008, how do I reference a dll that I know is valid but throws an error when added?

I have inherited a project from the powers that be, and, when first loading it up in VS 2008, I get an error right off the bat.

"A reference to XXX.dll could not be added.  Please make sure that the file is accessible, and that the assembly is a valid assembly or COM component."

The DLL is valid.  I've used it numerous times in many different applications and services, but I did my due dilligence and removed the reference, put a copy of the DLL i've used personally in its place and STILL get the error.

What can this mean?
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käµfm³d 👽Commented:
Is it a "resource only" DLL?
If your refering about an unmanaged COM DLL then register the library and then try adding it as a reference.
AndyAinscowFreelance programmer / ConsultantCommented:
Check the paths of the references for the project.  The dll might well be OK, just not in the directory the project is expecting it to be in.

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RichardRigaAuthor Commented:
thank you
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Visual Basic.NET

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