CCH Engagement tab missing in excel

First option

Open excel, then go to file -> options -> add-ins

Select Manage: COMs under dropdown box

Then click go

Checkmark the Pfx.Ribbon.ExcelAddIn to make it active

If that does not work, try a reinstall with the below instructions

Second Option

Close all applications (INCLUDING EXCEL)

• Go to add remove programs 
• Remove Pfx.Ribbon.ExcelAddIn

• Reinstall add in by going to C:\Pfx Engagement\WM
• Double click to run Pfx.Ribbon.ExcelAddIn

• Reboot or logoff (required)