Not sure if you figured this out. I’ve been trying to figure this out for a bit as it has forced my students to use QuickPost in the Dashboard of their sites.
I changed
if ( property_exists( $wp_query, 'query' ) && array_key_exists( 'page_id', $wp_query->query ) ) {
to
if ( property_exists( $wp_query, 'query' ) && array_key_exists( 'page_id', $wp_query ) ) {
I think it works now as the error is no longer showing up. I also noted that this only happens in IE, not in Chrome.
The code that rCampbell is posted is not too far off, as it no longer gives the plugin the chance to look for an array key in something that’s not an array. However, it also bypasses the check for the page_id variable entirely, which will make the plugin perform in unexpected ways.
I just posted version 0.5.1 of the plugin, though, and that contains modified code that should prevent this error message from coming up again. If you have a chance, try out the new version and let me know if that solves the problem. If not, I’ll have another go at fixing this.
