When attempting to install your Revit 2010 product, you receive the following error and the installation rolls back:
1: 5 2 Failed to Load FNP_ACT_Installer.dll. 3: 126
Solution
The error is caused by a conflict in a Macrovision DLL file on the machine, most often seen after installing AutoCAD 2010. AutCAD 2010 puts its version of that file on the system and may conflict with subsequent Revit installations. To resolve the error, save the appropriate .zip file for your Operating System below, extract the .dll file, and place it into the following directory, overwriting the existing version:
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