Please follow these steps to fix this issue:

1.       Close PentaCalc Pro

2.       Uninstall PentaCalc Pro from the Program Group

3.       Find and delete this whole folder and it’s contents…   c:\Users\”Your User”\Appdata\Roaming\ PentaCalc.  If you type %APPDATA%\PentaCalc in Windows explorer it will take you to this folder.

4.       Reboot

5.       Reinstall PentaCalc Pro

6.       It should work now