Probably linked to changes in promises affecting dialogs
|Resolved||Krinkle||T127328 Optimise critical rendering path|
|Resolved||Krinkle||T124742 Upgrade to jQuery 3|
|Resolved||matmarex||T166153 Issues with oojs-ui dialogs after updating to jQuery 3|
|Resolved||matmarex||T166150 Template dialog doesn't focus input after update to jQuery 3|
ve.ui.MWTemplateDialog tries to set the focus in its setup process. I'm not sure why this ever worked, the dialog is not supposed to be visible at this point, so you can't focus anything in it. It should use the ready process.