in Chrome console I get the notice
[Deprecation] document.registerElement is deprecated and will be removed in M73, around March 2019. Please use window.customElements.define instead. See https://www.chromestatus.com/features/4642138092470272 for more details.
(anonymous) @ editInPlace.js:9
In FireFox, IE 11, and EDGE the GUI simply did not work.
Quite by fluke, commenting out the single line 9 would allow the GUI to work and the depreciation message went away.