Mac OS X 10.13.04
Opera 56.0.3051.116
uBlock Origin 1.17.0

При включенном юБлок становятся серыми, не активными кнопки "Оправить" в ответе под комментарием и под статьей:
<spoiler title="Скриншот">
<img src="https://habrastorage.org/webt/ym/cz/6m/ymcz6mon2s3eurm91lgzplhe-gg.png" />
</spoiler>Курсор становится серой стрелкой с перечеркнутым кружком. На любой странице статьи, вот здесь, например.

После отключения юБлок надо перегрузить страницу и кнопки снова становятся активными
<spoiler title="Ошибки в консоли:">
FS500-loaded
/images/px.gif?ch=1&rn=8.884196884176948:1 Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
/images/px.gif?ch=2&rn=8.884196884176948:1 Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
mediator.mail.ru/script/2820404/:1 Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
browser.js:61 Opera has modified script or content on www.facebook.com (PATCH-1195, Facebook - block first character in the comment field from triggering a single key keyboard shortcut). See browser.js for details
VM128:23 Uncaught TypeError: s.indexOf is not a function
at check (<anonymous>:23:57)
at <anonymous>:32:9
at HTMLDivElement.<anonymous> (vendors.bundle.js:1)
at Function.each (jquery-1.8.3.min.js:2)
at init.each (jquery-1.8.3.min.js:2)
at init.$.fn.tabslet (vendors.bundle.js:1)
at HTMLDocument.<anonymous> (main.bundle.js:1)
at l (jquery-1.8.3.min.js:2)
at Object.fireWith [as resolveWith] (jquery-1.8.3.min.js:2)
at Function.ready (jquery-1.8.3.min.js:2)
at HTMLDocument.A (jquery-1.8.3.min.js:2)
mc.yandex.ru/metrika/watch.js:1 Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
connect.facebook.net/en_US/fbevents.js:1 Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
top-fwz1.mail.ru/js/code.js:1 Failed to load resource: net::ERR_BLOCKED_BY_CLIENT
</spoiler>

Если юБлок отключит, то ошибок нет:
<spoiler title="Заголовок спойлера">
FS500-loaded
?reply_to=19533968:24928 HTTP-Based Public Key Pinning is deprecated. Chrome 69 and later will ignore HPKP response headers. (Host: habr.com)
browser.js:61 Opera has modified script or content on www.facebook.com (PATCH-1195, Facebook - block first character in the comment field from triggering a single key keyboard shortcut). See browser.js for details
VM532 browser.js:61 Opera has modified script or content on www.facebook.com (PATCH-1195, Facebook - block first character in the comment field from triggering a single key keyboard shortcut). See browser.js for details
raven.min.js:2 HTTP-Based Public Key Pinning is deprecated. Chrome 69 and later will ignore HPKP response headers. (Host: habr.com)
</spoiler>