ADConnect Error - DeletingLicensedGroupNotAllowed

If you ever delete a group in Azure AD which is used for Group Licensing purposes you will receive an error in ADConnect similar to the screenshot above . 

The error states : "DeletingLicensedGroupNotAllowed"

The problem is that AD Connect does not specifically tell you which AD Group caused the problem. In most situations you realise you have an error in AD Connect a few hours or days later . 

What if it was Azure Active Directory clean up day and you deleted 200 groups ? How can I find which group is causing the problem ?  

Navigate to Azure Active Directory - > Groups and then Audit Logs . 

Click add filters and add Status . Then choose failure for status . Obviously within the failures you will find the one you are looking for . To resolve the error remove the license assignment from the group so the group can be deleted.