Migration Assistant on Mountain Lion does not let me deselect anything

I also found that users cannot be imported from a mac with server on it. I could never get a straight answer from an Engineer on why. I don't think they knew either but I suspect it's a misguided attempt at security in preventing users being migrated from a server and hacked later.

I've found two ways around the problem.

IF you setup a user on the destination drive with the same name & UID you can sometimes clone the original user or user content over to the destination using CCC or other program. Doesn't always work so try it if you feel like experimenting.

How the 2nd method is performed depends on whether you intend to continue running Server or not.

A) No need for server: then delete the server app and its prefs from the volume, do a search to make sure you get it all. Rerun the migration tool and if there are no server remains then, surprise! -the tool runs just fine.

B) If you need the server then clone the volume to another drive, connect the clone to the destination Mac and perform (A) above on it. During the clone you can skip the server app, prefs and also the entire NetBootSP0 folder. Saves time on copying and you need to delete it anyway.

As I write I have a similar problem on a mac with El Capitan. I had server, and I have read the other replies near this one. I am now trying to understand if Server has a way to restore from an old home folder disk image or home folder copy.

Do readers happen to know if Server's User stuff provides this? I suspect if such a thing existed, I would have found it by now.

I do know there is a support article saying how to restore like this without Server.