Plugin breaks functionality of the Insert module (CKeditor 4)

When using integrated CKEditor 4 + Insert module, and pressing "Insert" button:
- insert() fires at sites/all/modules/insert/insert.js:37
- insert() fires at sites/all/modules/wysiwyg/editors/js/ckeditor-3.0.js:230

JS error occuring at line 232 of the second js: CKEDITOR.instances[this.field].insertHtml(content);
with error `TypeError: x.getLast(...) is null` from sites/all/libraries/ckeditor/ckeditor.js:324:144

When I turn off this (ckeditor_image) recently installed module - Insert module works fine (via wysiwyg chain).