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.
Nemo filed this as bug 49320 (thanks) and it's fixed.