Extender/Script controls may not be registered before PreRender

If you receive an error similar to this, it’s time to look for a missing call to base.OnPreRender.

If you override OnPreRender(EventArgs e) in a custom control, the conventional wisdom says you need to remember to call base.OnPreRender(e). Recently, I ran into this issue and found out the hard way that the page which hosts your control also must call base.OnPreRender in its OnPreRender (if you override it at all).

I hope I saved someone an hour or two of debugging. Thanks to Daniel Balla for pointing me in the right direction.

Yes you did -- Thanks a lot....

Thanks you did save me an hour or two

Thanks. You did indeed save me some time.

I'll add to the comments here... yes, that did save a lot of time and a lot of head-desk action...

Thanks!

Cool.. thanks.

Thank you for posting this.

Could you help me ? I make a custom control which have a ScriptManager and a CalendarExtender .They were defined in the CreateChildControls.I didnot override OnPreRender. But I still had this
error(Extender controls may not be registered before PreRender.).
What's wrong?
I am sorry.I am a chinese.My english is bad.
Thanks.

sunfly,
have you managed to fix your problem?
I have the same problem and need a solution.