TYPO3 Core

I have this issue spontanously on trunk version. All is standard, nothing special configured, no extra tsConfig, just the setting from default install.

"The editor is being loaded. Please wait..."

when i switch to fullsceen then RTE loads, switching back the same error again.

found this error:
editor.getPluginInstance("Default") is null
cleanLater()("data[tt_content]¹⁸⁴[bodytext]")DefaultC...b35df9.js (Linie 175)
(?)()htmlarea...2cbbd5.js (Linie 311)
[Break on this error] editor.getPluginInstance("Default").clean();

(issue imported from #M12425)