Update : (a small messy writeup)
I removed the “old editor” (the extension) and re enabled the new one (“Gutenberg”).
https://www.brit-hotel-fumel.fr/contact/#piscine
still works well.
But : as soon as I login, and edit/open the “contact” page, or to be more precise : one of the pages where I have the webcam BB code, the Gutenberg editor bails out.
For me, after removing ALL extensions except WebCam, this combination does not work
Gutenberg + Webcam + PDF Embedder ( https://wp-pdf.com/ ) => Editing a page that contains the Webcam BB = no-go.
Gutenberg + Webcam = ok
Gutenberg + PDF Embedder = ok
When opening Guteberg, and the error shows up, it’s mentions :
….
/wp-content/plugins/react-webcam/js/vendor/react.min.js?ver=5.0:5951:3
….
/wp-includes/js/dist/vendor/react.min.js?ver=16.6.3:20:291
….
As found out before : double instances of react.min.js are included. The same code (== functions, etc), different versions = no go (of course).
What should be done is that React Webcam uses the build in the build-in (to WP)
/wp-includes/js/dist/vendor/react.min.js?ver=16.6.3:20:291
version and not includes it’s own (ancient) version.