“Microsoft SharePoint designer does not support editing non-SharePoint sites” – while trying to open a SharePoint 2016 site with SharePoint designer 2013, I got this error message.
- Simply close all instances of your SharePoint Designer and then reopen it.
- Check if client integration is enabled in Web Application settings from the Central Admin site.
- Clear SharePoint designer cache. Here is How to Clear SharePoint Designer Cache?
- Try re-installing SharePoint designer!