I'm having some issues adding a custom geocoder to ArcGIS online. The geocoder is working, it's been successfully published to one of our servers and I can add it to ArcMap and successfully use it to find roads. It was built using Arc Map 10.3
When adding it to AGOL I fill out all the details, click 'ok', then hit save. The website then hangs, I get a loading icon and that's it. I have tried it on different browsers, different machines, hosting the geocoder on different servers (10.2 and 10.3) and using a different AGOL user account.
Any one know whats going on?