I had installed the outlook Add-In and it had been running for a month or so and then suddenly it stopped appearing in Outlook.
The folders weren’t there and non of the functionality was showing.
I tried accessing CRM using the browser and the it didn’t give me the message saying I should install CRM Add-in for outlook.
After some investigation I found out the Add-In had been disabled! I have no idea when, how or who did this.
To see if the CRM Add-In is disabled go to
Outlook -> Options -> Add-Ins
This will then show you the list of Add-Ins and if they are active, inactive and disabled
From there look at the manage section at the bottom.
Use the drop down to select Disabled Items and press the GO button, select the CRM Add-in and choose enable.
Then change the drop down to Com Add-ins and press the GO button.
you can now tick the Microsoft Dynamics CRM tickbox.
You have now enabled Microsoft Dynamics CRM outlook Add-in.
You may have to restart outlook but after that CRM should once again be working in outlook.