This only happens if ajax response is not a valid JSON. This means there are some PHP debug message in ajax response. Please check the response in browser console.

In 2.3.8 widgets are registered using old deprecated method. This has been fixed in RC.

We have not tried with multiple language yet. RTL style need to be fixed.

Previously this functionality was existed in AnsPress but I have to remove it. And question already have pagination for answers. Also questions are generally not used for that purpose. https://gist.github.com/rahularyan/d17030b836e52a0b75b4

I tried to fix this issue today but it doesn’t seem to be happening with RC version. Hence I am considering this issue as solved.

I don’t think its AnsPress.

This is solved and pushed to master branch.

Have you tried re-saving the permalinks settings page? Sometimes permalinks get messed up and this sometimes solves the issue.