FranH

quick fix:

in folder “wp-content\plugins\front-end-editor\editor\”
rename “editor.js” to “editor.min.js” (or something else),
rename “editor.dev.js” to “editor.js”,
open “editor.js”,
find line 838
new fieldTypes[type]($el, type, filter, data)
and change it to

try {
    new fieldTypes[type]($el, type, filter, data);
}catch(err){;}

this should get the editor working.
(it worked for me, anyway.)

as far as i can tell, the error occurres if one item is rendered two times.