semanticforms JS error when I [Edit with form] my user page
TypeError: setting a property that has only a getter newBtnElement[attribute.name] = attribute.value;
adding &debug=1 to the URL shows it's coming from line 198 of https://translatewiki.net/w/extensions/SemanticForms/libs/SF_preview.js
I do get a form with a nifty Google Mapsgadget to set my location, but I think due to this JS error other code stops working, so e.g. [Show preview] doesn't work
Chromium doesn't report this error, but it reports 'SecurityError: DOM Exception 18' and Invalid 'X-Frame-Options' errors.
Thanks for the report. It should go into the bugzilla as we are running stock semantic extensions and we do not have capacity to fix issues in all those extensions.