Page Update Hangs

Hey,

I have a single page (as far as I know – I tested a few others with no issue) that hangs on “Update”.

The page is here: https://ucgeek.co/lync-updates/

If I completely remove all content from the page, it saves fine. My last save a couple of weeks back was fine, and this time all I added was a single table row. The page is unusually large with lots of tables, but nothing I would have thought would cause an issue.

The browser eventually gives up with ERR_CONNECTION_CLOSED.

How can I troubleshoot the cause of this?

Thanks,
Andrew