Sometimes Excel will disable Add-ins, and you will need to re-enable the Valcre Add-in. The following steps will get it re-enabled back into Excel for you:
1. Go to File -> Options
2. Go to Add-ins
3. Select "COM Add-ins" from the Manage dropdown. Then, select Go...
4. Check "Valcre" within the list and select OK
5. Select OK (you should now see the Valcre ribbon return to your Excel application).