Some processes on your computer, such as security features in Windows or regular Microsoft Outlook updates, can disable add-ins that you installed in Outlook, such as the Marketo Sales Insight add-in. This would cause the Marketo buttons to disappear from your Outlook.
To re-enable the add-in, follow these steps:
- Open Outlook.
- Go to File > Manage Add-ins.
- Locate the add-in "Marketo Insights" and check the box to turn the feature back on.