Gallery error 418

About 90% of the time, whenever opening the gallery on any browser except windows edge, the only text on screen is "Error 418"

This was the case on all 3 computers I've tried it on, and Edge was the only browser that worked. Of course on Mac, there is no working option it seems.

I've tried making sure flash was enabled, and any other website settings that would have the option of being enabled or disabled. I'm not sure what the issue or solution is, especially since error 418 has never really been a researched error, besides being joked about.