Steps to reproduce: 1. Visit <http://portal.office.com> and sign in. 2. Open Visio and create a new document. 3. Drag and drop a shape to the document. Then you will see an error message: Something went wrong. To continue editing please refresh or close the file and try again after some time.
<rdar://problem/48663949>
This regressed in <https://trac.webkit.org/changeset/242297/>.