Many Microsoft Dynamics CRM customers (Regardless OnPremise or Online) have the challenge with the Outlook plugin. The main challenge is that the plugin from time to time getting disabled in Outlook. Once the below solution is deployed the CRM Outlook client will always be activated.
Type Regedit (in Windows search) – navigate to:
Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Addins\crmaddin.RibbonAddin Change LoadBehaver value from 0 to 3