I had a little success creating a custom theme for a bit.
Followed the procedure for deleting themes outlined here when I wanted to remove one:
But after a while although I can upload the custom theme successfully.
I now get this error reported:
Fatal error: Error: ENOENT: no such file or directory, open 'C:\adapt\temp\5b97afcbf20a592fdcc7e1eb\adapt_framework\src\theme\adapt-contrib-vanilla\js\theme-block.js'
In module tree:
It appears to be that it is trying to access a file in the vanilla theme (but the path is wrong for the vanilla theme as well). Not sure how the theme/code is deciding to use that path. It's not in the bower.json file.