Microsoft is aware of issues impacting Add-ins when using its NEW version of the Outlook app. This may inspire users to want to revert back to the legacy version. Here is a help article to guide you.
Go back to Legacy Outlook for Windows
If you toggle into the new Outlook for Windows preview from classic Outlook for Windows, every time you launch Outlook you'll be redirected to the new Outlook. You can go back to classic Outlook by selecting the toggle in the new Outlook app.
There are 2 ways to revert the app in Windows.
Method 1
Click the toggle in the upper right corner of the app.
Method 2
Click Help in the app top menu. Select 'Go to Classic Outlook'.
Go back to Legacy Outlook for Mac
Similarly on Mac, if you've toggled the Legacy Outlook to off, you will be automatically brought to the New Outlook app. You can revert this by clicking on the Help menu and select Revert to Legacy Outlook.
**Important to Note - Email accounts added in the new Outlook for Mac will not automatically be added to Legacy Outlook, and vice versa. These account will need to be managed independently based on which app version is being used.
Feel free to reach out to GivingData customer support for assistance.