No problems with migrations no.
Hi, found the issue:
The problem was that the "name" element must be equal to the Folder name where the theme is located.
In my case the foldername was lowercase and the theme.json file was indicated with uppercase.
That's explained in the post. http://forum.asgardcms.com/post/35
No one has replied
Looks like your connection to AsgardCms was lost, please wait while we try to reconnect.