404 errors on multisite install

Hosting with 1and1
two sites on same account
/www.preview-classes.com/
/www.preview-education.com/
Both set up as Wordpress multisite
Subfolder installs
Both are relatively new, content being created and added
preview-education works fine
preview-classes shows 404 errors on most pages and admin
permalinks are set the same
remove /blog/slug is used

Any ideas how to get preview-classes working?
I had originally tried to set them both up as buddypress sites. Buddypress caused errors and was deactivated. BP installed pages remain.