We recently discovered that the “Error saving movie answer” might be appearing in certain browsers that use something called a “WebKit”. If your browser is not up to date, and the WebKit version is lower than the current one, you could be experiencing this error.
Here’s how it looks like:
For reference, here’s a thread where the error has been discussed before: http://forumhcinst.org/t/im-getting-an-error-message-on-every-other-movie/