CommentStreams:F1e6e20934e0f85afbf6f9dcba724467

I'm having an issue where if I try to save a page containing certain content, the page will not save. Pressing the save button on a page containing the problematic content goes to a blank page, save for the site header and footer, with no error message. The whole content prior to pressing the save button is lost.

I've tried in "private mode" in case it could be a browser configuration issue.

Here are two separate snippets which prevent saving a page: https://dpaste.com/BLHEEMZ34.

Thanks in advance to anyone who might have a clue as to what is happening.