Process is the same for Outlook/Word/Excel
Go to file > options > add ins
Then go to the drop down box at the bottom of that window and choose disabled items and click go, if OMS is in there enable it if it’s not there just go to next step
Now drop down to COM add ins and click go, then tick the box next to 3E Mattersphere and click ok to enable the add in
Close and reopen word and it should be active again