I am getting the error below when trying to register this addin

RegAsm : warning RA0000 : Registering an unsigned assembly with /codebase can ca
use your assembly to interfere with other applications that may be installed on
the same computer. The /codebase switch is intended to be used only with signed
assemblies. Please give your assembly a strong name and re-register it.
RegAsm : error RA0000 : Could not load file or assembly 'SolidWorksTools, Versio
n=2.0.0.0, Culture=neutral, PublicKeyToken=bd18593873b4686d' or one of its depen
dencies. The system cannot find the file specified.

Any ideas what SolidWorksTools, Version=2.0.0.0 is and why it cant be located?