The buttons in the rich text editor sometimes doesn't work.

[fjybiocs]

Click them and no response. Here are console logs:

mount-redraw.js:15 TypeError: Cannot set property 'value' of null
    at e.<anonymous> (index.js:143)
    at e.forEach.t.<computed> [as oncreate] (extend.js:37)
    at Function.a (render.js:30)
    at render.js:971
    at Function.a [as sync] (mount-redraw.js:14)
    at t.e.show (ComposerState.js:91)
    at DiscussionControls.js:193
    at new Promise (<anonymous>)
    at e.replyAction (DiscussionControls.js:184)
    at HTMLElement.onclick (ReplyPlaceholder.js:38)

index.es.js:4734 Uncaught TypeError: Cannot read property 'matchesNode' of null
    at lr.updateStateInner (index.es.js:4734)
    at lr.updateState (index.es.js:4705)
    at lr.dispatchTransaction (ProseMirrorEditorDriver.js:101)
    at lr.dispatch (index.es.js:4973)
    at Object.command (index.es.js:533)
    at t.e.run (MenuState.js:63)
    at e.r.click (CommandButton.js:32)
    at $.handleEvent (render.js:888)