​What is the Advanced support option RemoveExistingPermissionsWhenUnspecified=1, and when should it be used?

Answer:

This option is used to resolve any conflict of permission problems during certain types of document migration projects.

This support option is used to clear existing permissions from the Destination, before adding any new permissions.

The scenarios that this Advanced Option is used for, are as follows:

• Google Drive to OneDrive for Business
• Any supported Source to Dropbox

It can be added within Advanced Options, in the Support options text field, under the Support section. KB005100

The syntax is exactly as follows:

RemoveExistingPermissionsWhenUnspecified=1