Error: Only one instance of a ScriptManager can be added to the page

Question

I got this Error when I added ScriptManager on a "Site.Master" (Master Page)

All child webForm of site.Master that contains ScriptManager. produce this error.....

Only one instance of a ScriptManager can be added to the page.

help Thanks

Answer 1

use a ScriptManagerProxy on your child pages/user controls

http://msdn.microsoft.com/en-us/library/system.web.ui.scriptmanagerproxy(v=vs.110).aspx

Answer 2

You probably have another instance of in one of the pages /user controls that inherits from this master page.