Since 2017-11-03, Magento 2.3 includes a new «Tinymce3» (`Magento_Tinymce3`) module

dmitrii_fediuk (Dmitrii Fediuk) December 29, 2017, 1:52pm 2

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Since 2017-11-03, Magento 2.3 uses TinyMCE 4.6 instead of TinyMCE 3 as the native WYSIWYG editor