Reply To: Pop up errors

I did reactivate NextGen, but I have the same install on the other site and on that one I’ve not reactivated NextGen and it has the same issue:

EDIT: I’ve found the problem. This time it’s WordPress SEO plugin. That is the conflict. Having deactivated that it works fine. But obviously this is one of the most popular plugins for WordPress so ideally we need them both working in harmony. Cheers