Have you ever installed the CRM for Outlook client add-in and for some reason the add-in is disabled? No matter what, you cannot seem to enable it? Well, I know many others have, so I will include a few different steps that you can use to troubleshoot these types of issues.
1. One of the most common things I have run into with CRM On-Premise is that the machine the client is installed on is not a member of the domain that also contains CRM, but instead is only a workgroup machine. The requirements for this are that the CRM client machine must be in the domain that CRM also exists in or it must be in a trusted domain. In a workgroup, it is in neither and you will run into authentication issues with CRM and the add-in will continue to disable itself.
2. Ensure that you are on the latest build for CRM to ensure you are not running into a previously fixed issue with the ribbon and disabled add-in.
3. Once again, make sure no other Outlook add-ins are causing this issue. You can disable these by going into Outlook, clicking File| Options| Add-ins, and Go on COM Add-ins. Here, you can disable all add-ins except Microsoft Dynamics CRM to see if the issue still occurs. When here, make sure the Microsoft Dynamics CRM add-in is enabled.
4. Verify that Windows Live Essentials is installed.
5. Make sure you have a good and constant internet connection. Use the ORG latency tool by replacing the <org> with your organization name.
6. What is the LoadBehavior value in the following location: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\Outlook\Addins\crmaddin.Addin
This value should be set to 3
7. Ensure that the machine time of the server and client is within 5 minutes of each other. Also, make sure that the time zones are correct based on the machine location.
8. There may also be some antivirus that is changing the load behavior value and disabling the add-in. Therefore, disable completely or uninstall antivirus for testing.
9. Does this only occur on Citrix or terminal server environments?
10. Make sure that if using CRM Online, the URLs must not be blocked by the proxy or firewall: Microsoft Dynamics CRM Online IP Address Ranges
11. There have also been issues where the PST file of the default profile in Outlook that CRM is configured to is damaged. Therefore, try creating a new Outlook profile and reconfigure the CRM client to this profile.
12. Also, are you using Exchange Cached mode in Outlook? One thing you can test is disabling this or enabling it, depending on your current settings, to see if the issue continues.