If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
Can you save it to Drafts and then see it in the Drafts section (formatted as it would be if published)? It's a good idea to do this in any case, to fix any issues with formatting before publishing. After that, "you've made changes to the article" at least won't be true, so the issue could be isolated further. If that doesn't work, start another article with "Hello World" content, make sure you succeed in saving it to Drafts and observing the result, then replace its content with your article.
Thanks. It works now. Turns out the error was with the hyperlinks in my table of contents.