When I try to activate the ChemDraw for Excel Add-In, I get an error about an invalid checkpoint or invalid entry point in CFXLib.dll.

When I try to activate the ChemDraw for Excel Add-In, I get an error about an invalid checkpoint or invalid entry point in CFXLib.dll.

This problem is caused by the 6.0 path entry being before the 7.0 entry. The solution is to disable all CambridgeSoft Add-Ins from Excel, then quit Excel. Next, do a Find File for the 6.0 CFXLib.dll and rename it to something else like CFXLib.old. After doing a Find File, right click on the first CFXLib.dll that you find and choose Properties. Click on the Version tab to make sure it is version 6.0 before renaming. Now launch Excel, and add the ChemDraw for Excel Add-In.