Summary:

After installing the Outlook Plugin, the tab is not shown and no errors are appearing when you try to enable to plugin.

Symptoms:

If you go into options -> add-ins and manage com add-ins the box for CRM outlook plugin remains unticked and will not change.

Description 

No errors are shown even if debugging logs are enabled

Resolution / Fix:

Go to Outlook Options -> Add-Ins -> manage Disabled Items and click 'Go' as shown here:

Description 

You can click on the disabled outlook add-in and click enable. You will need to restart Outlook to see the changes.

If the tab is still hidden, select COM Add-ins and make sure the box is ticked.