My validators stop working when placed in an updatepanel. I have also tried the validatorcallout...still no luck...they just dont validate..

Then I found this link: http://blogs.msdn.com/mattgi/archive/2007/01/23/asp-net-ajax-validators.aspx

which adviced to add the following in my web.config:
tagMapping>
    <add tagType="System.Web.UI.WebControls.CompareValidator"           mappedTagType="Sample.Web.UI.Compatibility.CompareValidator, Validators, Version=1.0.0.0"/>
    <add tagType="System.Web.UI.WebControls.CustomValidator"            mappedTagType="Sample.Web.UI.Compatibility.CustomValidator, Validators, Version=1.0.0.0"/>
    <add tagType="System.Web.UI.WebControls.RangeValidator"             mappedTagType="Sample.Web.UI.Compatibility.RangeValidator, Validators, Version=1.0.0.0"/>
    <add tagType="System.Web.UI.WebControls.RegularExpressionValidator" mappedTagType="Sample.Web.UI.Compatibility.RegularExpressionValidator, Validators, Version=1.0.0.0"/>
    <add tagType="System.Web.UI.WebControls.RequiredFieldValidator"     mappedTagType="Sample.Web.UI.Compatibility.RequiredFieldValidator, Validators, Version=1.0.0.0"/>
    <add tagType="System.Web.UI.WebControls.ValidationSummary"          mappedTagType="Sample.Web.UI.Compatibility.ValidationSummary, Validators, Version=1.0.0.0"/>
</tagMapping>

But then I get the error:
Could not load file or assembly 'Validators, Version=1.0.0.0' or one of its dependencies. The system cannot find the file specified.

I've read a few blogs but nothing works...any feedback from the moderators?

Has this been fixed in asp.net 3.0?
 

Peter Smith:

... But then I get the error:
Could not load file or assembly 'Validators, Version=1.0.0.0' or one of its dependencies. The system cannot find the file specified....

 Did you add the assembly reference to your web project?

 uhmm....where can I find that option and where is the assembly usually located? :$

Check your "References" folder in your web project for "Validators" and if it's not there you'll want to add the dll "Validators" after downloading it from his blog.