I've taken the instructor-led classes on Utility Networks and done tons of tutorials, but I still find it difficult to troubleshoot errors. Has anyone ever seen this error? I realize the image is really small. The red box says, "Edit operation failed. Message: Cannot acquire a lock."

The user is editing on a version and just randomly gets this error from time to time. Our previous editing service was so buggy that I published a brand new one. This error pops up on the new one.
We have a ticket in with Esri support because his versions won't reconcile with DEFAULT. I don't have that problem, so it's even stranger that one user would have the issue and I don't. Granted, I am an admin and he isn't, but there's just so little to go on that I'm grasping at straws.