After updating our clusters with Hot Fix 71 yesterday we are now unable to see any historic data from before the hot fix was applied.
Release : 10.7.0
Component : APM
Problem was due to the metadata folder being deleted prior to applying the hotfix. This should not be done as the Eneterprise Manager will not recreate the metadata.
Customer will proceed and accept historic data is lost - live data is of more importance.
It is possible to merge the data if the metadata files from before the upgrade are available however this is a complex and manual process - contact support if this is required.