To see if the program is still working please enable "Show scanned registry key in status bar" option in the Advanced Settings before scan and resize program window to see how changes scanned registry key line. If key is not changed for a long time, please write down full registry key name where Registry Healer has stopped.
Is that key the same every time you run RH scan?
If the key is always the same, then you may add it into excluded list. Please refer to the topic on how to add a key into an exclusion list. Ensure you selected correct category of excluded list to add into. Or add that registry key into all exclusion lists.
Contact to support with your new excluded registry keys so we can check if they need to be added into the default excluded lists for all new Registry Healer versions.