I’m not sure if EVERYONE is having this problem or not, but if you have downloaded and installed the Trimblelink for C3D 2011, it shows up on the ribbon when C3D is opened and everything works fine. However, upon exiting the program, and re-opening it, Trimblelink is gone!! I have contacted Trimble support about this issue and they told me that what they have found so far is that it might be a user profile issue. Not the case. Another way is to delete the registry key located at: HKEY_CURRENT_USER\Software\Autodesk\AutoCAD\R18.1\ACAD-9000:409\Applications\TrimbleLink
This will allow the .arx file to re-initiate and it will show back up in the ribbon, but once again, as soon as you exit the program and re-open it, the same thing occurs. I am working with Trimble on this issue and as soon as I hear back from them with a definite solution, I will post it.
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