Forum .LRN Q&A: Re: error adding classes when everything else worked fine :(

I'm having the same problem (can't add classes or communities) but I haven't installed twice any modules.

When I run the query:

select name from portal_datasources group by name having count(name) > 1;

It returns 0 rows.

I've downloaded the sources a few days before Alfred.

Any ideas would be appreciated.