Problem: Invalid argument wp-includes/query.php on line 1702

the same as for me

kennykellogg, do you use multisite in your WordPress?

I have multisite and after upgrade to wordpress 3.6 have the same error.
I disable NExtgen and it’s fine.

In other my wordpress site everythink is fine (no multisite).

Ok i find this. They working on it:

https://www.ads-software.com/support/topic/warning-invalid-argument-supplied-for-foreach-after-plugin-upgrade-on-v2?replies=9

The problem is in NExtgen 2.0 and multisite.

Ok i I go back to an earlier version of NextGEN Gallery and it’s work for me. Remember to don’t delete your NextGen plugin in your back office, you lost your images!!!

@btekbtek, @stal1n: Would either of you be willing submit login credentials so we can trouble shoot this on your sites? If you, you can submit credentials here:

https://www.nextgen-gallery.com/report-bug/

Be sure to include a link to this thread and say Erick asked for credentials. There are things we need to work on for multisite, but you definitely should be able activate without these errors.

Thanks.