Hi,
Microsoft Office applications can disable add-ins that behave unexpectedly. If Outlook does not load your add-in when it starts, it might have hard disabled or soft disabled your add-in.
Hard disabling can occur when an add-in causes the application to close unexpectedly. While soft disabling can occur when an add-in produces an error that does not cause the application to unexpectedly close.
Note: When you re-enable a soft-disabled add-in, the application immediately attempts to load the add-in. If the problem that initially caused the application to soft disable the add-in has not been fixed, the application will soft disable the add-in again.
There could be a couple of reasons that Outlook hard disabled or soft disabled the add-in, for example, the anti-virus program might block the add-in load, or there was a conflict with other add-ins that are being loaded in Outlook. Disable all other
Add-Ins except the one in question and retry.
The good thing is that you have found the solution to keep the add-in on in Outlook, we can find more details from this KB below:
How to enable the add-in for Business Contact Manager in Outlook
As long as you modified the LoadBehavior value to 3, the add-in should always be loaded.
I hope the information is helpful to you.
Regards,
Melon Chen
Forum Support