Legal Review Collector will copy files from Matter A to Matter B, however not from B to A. An 'Invalid Key Error' is received and the collection fails.
This problem may occur if matter B has fields that are not in matter A.
Fields from the source matter must exist for documents to be successfully collected to the destination matter. If there are fields that do not exist in the destination matter, they can be configured to be ignored in the matter-specific 'ZyLAB.EDiscovery.Collectors.LegalReview.dll.xml' configuration file as in the following example:
<Field name="ThreadId" />
<Field name="RootMessageId" />
<Field name="EmailTopic" />
After changing the file, restart the processing service on the Processing Nodes, then retry the collection.