As soon as the textarea/editor under "Your answer" got focus, the "Add answer" button get disabled.
I've a lot of errors in the console:

Consider using 'dppx' units instead of 'dpi', as in CSS 'dpi' means dots-per-CSS-inch, not dots-per-physical-inch, so does not correspond to the actual 'dpi' of a screen. In media query expression: only screen and (-webkit-min-device-pixel-ratio: 1.5), only screen and (min-resolution: 144dpi)
DEPRECATED: jquery.autocomplete.js - See https://ecosystem.atlassian.net/browse/AUI-393 batch.js:9429
tinymce.documentBaseURL = http://<base_url>/confluence/s/d41d8cd98f00b204e9800998ecf8427e…cdb564ae4b/_/download/resources/com.atlassian.plugins.editor/tinymcesource batch.js:9429
Creating AJS.Rte.BootstrapManager object. batch.js:9429
AJS.Rte.BootstrapManager created batch.js:9429
tinyMce-autocomplete-settings initialising batch.js:9429
tinyMce-autocomplete-util starting batch.js:9429
tinyMce-autocomplete-control starting batch.js:9429
tinyMce-autocomplete-manager starting batch.js:9429
tinyMce-autocomplete-settings-links initialising batch.js:9429
tinyMce-autocomplete-settings-media initialising batch.js:9429
tinyMce-autocomplete-settings-macro initialising batch.js:9429
AJS.Confluence: run binder components batch.js:9429
confluence-keyboard-shortcuts initialising batch.js:9429
draft-changes initialising batch.js:9429
TinyMceAdapter: initTinyMce batch.js:9429
TinyMceAdapter: auto-start=true. Calling AJS.Rte.BootstrapManager.initialise() batch.js:9429
Bootstrap:initialise: Initialising TinyMce version 3.4.9-atlassian-11 batch.js:9429
RTE refresh.settings handler: Modifying settings with values derived from the editor DOM. batch.js:9429
RTE refresh.settings handler: The editor container has the resize class so the Editor will grow as required. batch.js:9429
Bootstrap:initialise: executing tinymcePluginInits batch.js:9429
Bootstrap: set locale translations batch.js:9429
Script for [atlassian] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [auiwindowmanager] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [emotions] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confluence] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [macroplaceholder] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [customtoolbar] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [propertypanel] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [keyboardshortcuts] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confmonospace] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confcharmap] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [lists] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confluencepaste] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [cursorTarget] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confluencecleanupplugin] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [conftable] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confluencepastetableplugin] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confluencepastemacroplugin] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [showformat] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [highlightnode] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [iosediting] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [searchreplace] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [autoconvert] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confluencelist] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [deletecommand] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [draggable] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [confluencesortabletablesplugin] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [textplaceholders] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [autoresize] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [jiraconnector] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [insertmention] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [linkbrowser] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
Script for [autocomplete] will not be loaded by TinyMCE. Please use Atlassian's requireResource. batch.js:9429
initPlugin: initialise auiwindowmanager batch.js:9429
initPlugin: finished initialisation of auiwindowmanager batch.js:9429
initPlugin: initialise emotions batch.js:9429
initPlugin: finished initialisation of emotions batch.js:9429
initPlugin: initialise confluence batch.js:9429
initPlugin: finished initialisation of confluence batch.js:9429
initPlugin: initialise macroplaceholder batch.js:9429
initPlugin: finished initialisation of macroplaceholder batch.js:9429
initPlugin: initialise customtoolbar batch.js:9429
initPlugin: finished initialisation of customtoolbar batch.js:9429
initPlugin: initialise propertypanel batch.js:9429
init property panel plugin batch.js:9429
initPlugin: finished initialisation of propertypanel batch.js:9429
initPlugin: initialise keyboardshortcuts batch.js:9429
Init Editor Keyboard shortcuts plugin batch.js:9429
initPlugin: finished initialisation of keyboardshortcuts batch.js:9429
initPlugin: initialise confmonospace batch.js:9429
initPlugin: finished initialisation of confmonospace batch.js:9429
initPlugin: initialise confcharmap batch.js:9429
initPlugin: finished initialisation of confcharmap batch.js:9429
initPlugin: initialise lists batch.js:9429
initPlugin: finished initialisation of lists batch.js:9429
initPlugin: initialise confluencepaste batch.js:9429
initPlugin: finished initialisation of confluencepaste batch.js:9429
initPlugin: initialise cursorTarget batch.js:9429
initPlugin: finished initialisation of cursorTarget batch.js:9429
initPlugin: initialise confluencecleanupplugin batch.js:9429
initPlugin: finished initialisation of confluencecleanupplugin batch.js:9429
initPlugin: initialise conftable batch.js:9429
initPlugin: finished initialisation of conftable batch.js:9429
initPlugin: initialise confluencepastetableplugin batch.js:9429
initPlugin: finished initialisation of confluencepastetableplugin batch.js:9429
initPlugin: initialise confluencepastemacroplugin batch.js:9429
initPlugin: finished initialisation of confluencepastemacroplugin batch.js:9429
initPlugin: initialise showformat batch.js:9429
initPlugin: finished initialisation of showformat batch.js:9429
initPlugin: initialise iosediting batch.js:9429
initPlugin: finished initialisation of iosediting batch.js:9429
initPlugin: initialise searchreplace batch.js:9429
initPlugin: finished initialisation of searchreplace batch.js:9429
initPlugin: initialise autoconvert batch.js:9429
initPlugin: finished initialisation of autoconvert batch.js:9429
initPlugin: initialise confluencelist batch.js:9429
initPlugin: finished initialisation of confluencelist batch.js:9429
initPlugin: initialise deletecommand batch.js:9429
initPlugin: finished initialisation of deletecommand batch.js:9429
initPlugin: initialise draggable batch.js:9429
initPlugin: finished initialisation of draggable batch.js:9429
initPlugin: initialise confluencesortabletablesplugin batch.js:9429
initPlugin: finished initialisation of confluencesortabletablesplugin batch.js:9429
initPlugin: initialise textplaceholders batch.js:9429
initPlugin: finished initialisation of textplaceholders batch.js:9429
initPlugin: initialise autoresize batch.js:9429
initPlugin: finished initialisation of autoresize batch.js:9429
initPlugin: initialise jiraconnector batch.js:9429
initPlugin: finished initialisation of jiraconnector batch.js:9429
initPlugin: initialise insertmention batch.js:9429
initPlugin: finished initialisation of insertmention batch.js:9429
initPlugin: initialise linkbrowser batch.js:9429
initPlugin: finished initialisation of linkbrowser batch.js:9429
initPlugin: initialise autocomplete batch.js:9429
initPlugin: finished initialisation of autocomplete batch.js:9429
Editor:init iframe base href=http://<base_url> batch.js:9429
event.returnValue is deprecated. Please use the standard event.preventDefault() instead. batch.js:3528
Editor:setupIframe: dispatch onPreInit batch.js:9429
Editor:setupIframe: dispatch controlManager onPostRender batch.js:9429
Editor:setupIframe: dispatch onPostRender batch.js:9429
Editor:setupIframe: dispatch onInit batch.js:9429
customtoolbar: ed.onInit function batch.js:9429
customtoolbar: finished ed.onInit function batch.js:9429
Editor:setupIframe: Callback setupcontent_callback batch.js:9429
Editor:setupIframe: Completed setupcontent_callback batch.js:9429
Editor:setupIframe: Callback init_instance_callback batch.js:9429
Editor:setupIframe: Completed init_instance_callback batch.js:9429
AJS.Rte.Init:onInit oninit callback batch.js:9429
Enabling Chunky Tooltip for the editor batch.js:9429
add-handler.property-panel: panel name = link batch.js:9429
add-handler.property-panel: panel name = image batch.js:9429
add-handler.property-panel: panel name = macro batch.js:9429
Migration duration: selector: 0ms; migration: 0ms batch.js:9429
add-handler.property-panel: panel name = variable batch.js:9429
Set mode: richtext batch.js:9429
Bootstrap: editor-auto-focus=false. Do not focus the editor automatically. batch.js:9429
Bootstrap:initialise: After editor TinyMCE init. batch.js:9429
Creating iframes com.atlassian.mywork.mywork-confluence-host-plugin:mw-header-anchor.js:46
Autocomplete enabled, adding keyPress listener batch.js:9429
AJS.MacroBrowser.loadModel - starting batch.js:9429
AJS.MacroBrowser.loadModel - complete, 2 macros loaded batch.js:9429
Analytics log cq.JS Error.Uncaught TypeError: Object #<Object> has no method 'replace'[

{"message":"http://<base_url>/confluence/s/d41d8cd98f00b204e9800998ecf8427e…4ae4b/_/download/contextbatch/js/editor,atl.general,macro-browser/batch.js (25810)"}

] batch.js:174
Uncaught TypeError: Object #<Object> has no method 'replace' batch.js:25810
Analytics log cq.JS Error.Uncaught TypeError: Object #<Object> has no method 'replace'[

{"message":"http://<base_url>/confluence/s/d41d8cd98f00b204e9800998ecf8427e…4ae4b/_/download/contextbatch/js/editor,atl.general,macro-browser/batch.js (25810)"}

] batch.js:174
Uncaught TypeError: Object #<Object> has no method 'replace' batch.js:25810
Resource interpreted as Script but transferred with MIME type text/html: "https://id.atlassian.com/profile/linkAccount.action?application=sac&continu…lector%2dplugin%3aissuecollector%2dembededjs%2ejs%3fcollectorId%3deb9d28f6". batch.js:8125
Analytics log [cq.JS Error.Script error.][

{"message":" (0)"}

] batch.js:174
Uncaught SyntaxError: Unexpected token < linkAccount.action:3
Analytics log cq.JS Error.Uncaught TypeError: Object #<Object> has no method 'replace'[

{"message":"http://<base_url>/confluence/s/d41d8cd98f00b204e9800998ecf8427e…4ae4b/_/download/contextbatch/js/editor,atl.general,macro-browser/batch.js (25810)"}

] batch.js:174
Uncaught TypeError: Object #<Object> has no method 'replace' batch.js:25810
Analytics log cq.JS Error.Uncaught TypeError: Object #<Object> has no method 'replace'[

{"message":"http://<base_url>/confluence/s/d41d8cd98f00b204e9800998ecf8427e…4ae4b/_/download/contextbatch/js/editor,atl.general,macro-browser/batch.js (25810)"}

] batch.js:174
Uncaught TypeError: Object #<Object> has no method 'replace' batch.js:25810
Analytics log cq.JS Error.Uncaught TypeError: Object #<Object> has no method 'replace'[

{"message":"http://<base_url>/confluence/s/d41d8cd98f00b204e9800998ecf8427e…4ae4b/_/download/contextbatch/js/editor,atl.general,macro-browser/batch.js (25810)"}

] batch.js:174
Uncaught TypeError: Object #<Object> has no method 'replace' batch.js:25810
Resource interpreted as Font but transferred with MIME type text/plain: "chrome-extension://pioclpoplcdbaefihamjohnefbikjilc/fonts/GothamSSm-Medium.otf". filing_tools.html:1
Resource interpreted as Font but transferred with MIME type text/plain: "chrome-extension://pioclpoplcdbaefihamjohnefbikjilc/fonts/GothamSSm-Bold.otf". share_tools.html:1
Resource interpreted as Font but transferred with MIME type text/plain: "chrome-extension://pioclpoplcdbaefihamjohnefbikjilc/fonts/GothamSSm-Book.otf". global_tools.html:1
POST http://<base_url>/confluence/rest/questions/1.0/questions/2621558/answerDrafts 415 (Unsupported Media Type)