1. Check for service releases for Microsoft Excel. This is a known issue for Excel 2010 SR1. Install later service packs.
2. Check for COM add-ins installed in Excel which might conflict with MasterMine. Users often have more Add-ins installed than they use, including old, non-functional ones.
To turn off add-ins in Excel (depending on version), click "File", "Options", and "Add-ins". Then use the Add-in manager dialog (in 2010, this is lower central in the Add-ins dialog) to manage (uninstall or temporarily turn off) selected add-ins. Be sure especially to look at COM add-ins.