So now it is fixed, but what caused the problem in the first place? The Outlook client and the IE client use a shared cookie. If you have the CRM Outlook client installed and Outlook is running, launching CRM from IE will cause the buttons to disappear. To bring them back, you must delete cookies.
To prevent this from happening in the future simply make sure Outlook is not using the same URL as you use when accessing IE. I like to have Outlook use the IP address of the CRM server and let the user type the machine name, or friendly name, in IE.
For example, if your CRM server is called "CRMServer" and the IP address is 192.168.1.1, the best way to set up Outlook is to modify the registry so the Outlook client is pointing to the server IP Address. NOTE: IF YOU ARE NOT FAMILIAR WITH MODIFYING THE REGISTRY, YOU SHOULD LEAVE THIS PROCESS TO YOUR SYSTEM ADMIN, you can create serious problems for your computer. In the registry, go to HKEY_CURRENT_USER -> Software ->Microsoft -> MSCRM Client. Find the 5 entries that point to the CRM installation and change the machine name to the IP address. Disappearing button problem solved.
If you're still having a problem with Disappearing Custom Buttons, contact
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