If the above doesn't work, open Excel and go to File --> Options --> Advanced. Add-ons --> 'Manage' at the bottom —> 'COM Add-ins' --> 'Go...' --> 'Dose for Excel' is checked. Check to see if it works now.
The 'Dose' tab is absent, which is a concern.
Whether the above fails, download and install the VSTO 2010 Runtime from the following link, then reopen Excel to see if it works: