We have a content Farm and Enterprise Services (ESS) Farm (where UPA is hosted), content Farm consumes UPA from ESS farm (all SharePoint 2010 obviously)
Whenever we try to load a Edit Profile Page it gives an error:
To keep everyone updated the issue was resolved, the JSON handler entry in the web.config (of our Mysite web-app as we were accessing EditProfile page from mysite) was missing and hence the errors.
After adding that entry everything started showing up.
<add name="JSONHandlerFactory" path="*.json" verb="*" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=188.8.131.52, Culture=neutral, PublicKeyToken=31bf3856ad364e35" resourceType="Unspecified" preCondition="integratedMode" />