updatepanel broker

Could be an unrelated compilation error in your site... or perhaps a tag that isn't closed.

Also, check outhttp://blogs.visoftinc.com/archive/2007/09/23/asp.net-ajax--updatepanel-not-working--common-problems.aspx for some other tips on UpdatePanel's not working.

-Damien

thank you

sorry it does not solve my problem

Try setting the UpdateMode to Conditional.

Also see:http://www.ben-rush.net/blog/PermaLink.aspx?guid=90aec101-d41f-4c07-bcf1-bdd48086c945&dotnet=consultant andhttp://forums.asp.net/p/1046285/1481792.aspx

-Damien

I found the problem

this is a strange interaction with a Component Art Treeview.

I don't know why, but it's working now

Try to set in web.config

<xhtmlConformance mode="Legacy" />