Let me assist you in merging clients, subuzz.
Before you merge them, make sure they don't have sub-customers. If they do, you'll need to make them into regular customers. Also, the name in the Display name as field should be exactly the same as the name of the client profile you want to keep.
Please check these links for the detailed steps:
In addition, I'd like to know the exact error message you encountered. If it says "Request Failed! Client Data could not be retrieved", our team is now investigating it. You'll want to reach out to our Customer Support Team for updates about this issue.
The new "Help" menu interface:
For the old "Help" menu:
Leave a comment below if you have more questions. We'll respond as soon as we can.