We have fixed an issue in XenForo 2.1.6 which may have led to JavaScript errors on pages with checkboxes that have a "Select all" checkbox.https://xenforo.com/community/threads/xf-checkall-no-longer-works-as-expected.173871/
We have released XenForo 2.1.6 Patch 1 to resolve this.You can perform the upgrade directly from your control panel by going to Tools > Check for upgrades. You can also download the update from your Customer area.