in ACP when select Users => Batch update users and when you select filters, after results are shown, if I click on link View or filter matches and make selection (or not make any changes) and than click on button Batch Update Selected then this error happened. If I go back and click refresh, still same error after clicking on button Batch Update Selected
Interesting is that this errors show up when many members are listed in result (600+)
I use XenForo 1.4.0 (with security patch file), also error shws with all add-ons disabled. I have only default style.