Last modified: 2011-04-30 01:20:40 UTC
1. Start a new installation via the web interface at blah.blah/wiki/config/
2. Fill a few fields eg. WikiName, ContactEmail etc.
3. Choose Copyright as "A Creative Commons license - choose"
4. Click Choose
5. Choose the two options. Click "proceed"
You are returned to the mediawiki config form but all the fields you had filled in earlier are now empty (eg. WikiName, ContactEmail etc.)
This is actually a forgotten oldie -- bug 2837. There's a patch on that bug but it's pretty old and probably needs to be tidied up.
*** This bug has been marked as a duplicate of bug 2837 ***