That's ridiculous in any way seen. Try to execute my answer-form-adding JavaScript:
javascript:document.getElementsByClassName("bottom-notice")[0].innerHTML='<form%20id="post-form"%20action="/questions/'+window.location.href.split('/')[4]+'/answer/submit"%20method="post"%20class="post-form"><input%20type="hidden"%20id="post-id"%20value="'+window.location.href.split('/')[4]+'"><input%20type="hidden"%20id="qualityBanWarningShown"%20name="qualityBanWarningShown"%20value="false"><h2%20class="space">Your%20Answer</h2><script>StackExchange.ready(function()%20{initTagRenderer("bug%20feature-request%20discussion%20support".split("%20"),%20"faq%20status-completed%20status-declined%20status-bydesign%20status-norepro%20status-reproduced%20status-planned%20status-deferred%20status-review%20featured%20community-ads".split("%20"));prepareEditor({heartbeatType:%20\'answer\',bindNavPrevention:%20true,postfix:%20"",onDemand:%20false,discardSelector:%20".discard-answer"});});</script><div%20id="post-editor"%20class="post-editor"><div%20style="position:%20relative;"><div%20class="wmd-container"><div%20id="wmd-button-bar"%20class="wmd-button-bar"><ul%20id="wmd-button-row"%20class="wmd-button-row"><li%20class="wmd-button"%20id="wmd-bold-button"%20title="Strong%20<strong>%20Ctrl+B"%20style="left:%200px;"><span%20style="background-position:%200px%200px;"></span></li><li%20class="wmd-button"%20id="wmd-italic-button"%20title="Emphasis%20<em>%20Ctrl+I"%20style="left:%2025px;"><span%20style="background-position:%20-20px%200px;"></span></li><li%20class="wmd-spacer%20wmd-spacer1"%20id="wmd-spacer1"></li><li%20class="wmd-button"%20id="wmd-link-button"%20title="Hyperlink%20<a>%20Ctrl+L"%20style="left:%2075px;"><span%20style="background-position:%20-40px%200px;"></span></li><li%20class="wmd-button"%20id="wmd-quote-button"%20title="Blockquote%20<blockquote>%20Ctrl+Q"%20style="left:%20100px;"><span%20style="background-position:%20-60px%200px;"></span></li><li%20class="wmd-button"%20id="wmd-code-button"%20title="Code%20Sample%20<pre><code>%20Ctrl+K"%20style="left:%20125px;"><span%20style="background-position:%20-80px%200px;"></span></li><li%20class="wmd-button"%20id="wmd-image-button"%20title="Image%20<img>%20Ctrl+G"%20style="left:%20150px;"><span%20style="background-position:%20-100px%200px;"></span></li><li%20class="wmd-spacer%20wmd-spacer2"%20id="wmd-spacer2"></li><li%20class="wmd-button"%20id="wmd-olist-button"%20title="Numbered%20List%20<ol>%20Ctrl+O"%20style="left:%20200px;"><span%20style="background-position:%20-120px%200px;"></span></li><li%20class="wmd-button"%20id="wmd-ulist-button"%20title="Bulleted%20List%20<ul>%20Ctrl+U"%20style="left:%20225px;"><span%20style="background-position:%20-140px%200px;"></span></li><li%20class="wmd-button"%20id="wmd-heading-button"%20title="Heading%20<h1>/<h2>%20Ctrl+H"%20style="left:%20250px;"><span%20style="background-position:%20-160px%200px;"></span></li><li%20class="wmd-button"%20id="wmd-hr-button"%20title="Horizontal%20Rule%20<hr>%20Ctrl+R"%20style="left:%20275px;"><span%20style="background-position:%20-180px%200px;"></span></li><li%20class="wmd-spacer%20wmd-spacer3"%20id="wmd-spacer3"></li><li%20class="wmd-button"%20id="wmd-undo-button"%20title="Undo%20-%20Ctrl+Z"%20style="left:%20325px;"><span%20style="background-position:%20-200px%20-20px;"></span></li><li%20class="wmd-button"%20id="wmd-redo-button"%20title="Redo%20-%20Ctrl+Shift+Z"%20style="left:%20350px;"><span%20style="background-position:%20-220px%20-20px;"></span></li><li%20class="wmd-button%20wmd-help-button"%20id="wmd-help-button"%20title="Markdown%20Editing%20Help"%20style="right:%200px;"><span%20style="background-position:%20-240px%200px;"></span></li></ul></div><textarea%20id="wmd-input"%20class="wmd-input%20processed"%20name="post-text"%20cols="92"%20rows="15"%20tabindex="101"%20data-min-length=""></textarea><div%20class="grippie"%20style="margin-right:%201px;"></div></div></div><div%20class="fl"%20style="margin-top:%208px;%20height:24px;"> </div><div%20id="draft-saved"%20class="draft-saved%20community-option%20fl"%20style="margin-top:%208px;%20height:24px;%20display:none;">draft%20saved</div><div%20id="draft-discarded"%20class="draft-discarded%20community-option%20fl"%20style="margin-top:%208px;%20height:24px;%20display:none;">draft%20discarded</div><div%20class="community-option"><input%20id="communitymode"%20name="communitymode"%20type="checkbox"><label%20for="communitymode"%20title="Marking%20an%20answer%20community%20wiki%20encourages%20others%20to%20edit%20it%20by%20lowering%20the%20reputation%20barrier%20required%20to%20edit.%20However,%20you%20will%20not%20gain%20any%20upvote%20reputation%20from%20it.%20This%20cannot%20be%20undone.">community%20wiki</label></div><div%20id="wmd-preview"%20class="wmd-preview"></div><div></div><div%20class="edit-block"><input%20id="fkey"%20name="fkey"%20type="hidden"%20value=""><input%20id="author"%20name="author"%20type="text"></div></div><div%20style="position:%20relative;"></div><div%20class="form-submit%20cbt"><input%20id="submit-button"%20type="submit"%20value="Post%20Your%20Answer"%20tabindex="110"><a%20href="#"%20class="discard-answer%20dno">discard</a></div></form>'
(Either from the top bar or console; if latter then remove javascript:
prefix)
Then click "Post Answer." It should reload writing an additional answer form and saying "Body is missing". If it behaves this way, everything okay; you get the full-featured answer form.
If no form appears, execute the script again, fill the answer body with some bloat your answer and post - the disadvantage of this is the preview not working - but you can write in the answer form to another question and submit there.