Hi,

I have a telerik RadTabStrip inside ajax UpdatePanel in my web page and when i navigate between the tabs, i get this wiered error "Invalid JSON primitive". Below is the stack trace of this error.

Type	System.ArgumentException
Source	System.Web.Extensions
Method	DeserializePrimitiveObject
Message	Invalid JSON primitive: .
Trace	at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializePrimitiveObject() at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal(Int32 depth) at System.Web.Script.Serialization.JavaScriptObjectDeserializer.BasicDeserialize(String input, Int32 depthLimit, JavaScriptSerializer serializer) at System.Web.Script.Serialization.JavaScriptSerializer.Deserialize(JavaScriptSerializer serializer, String input, Type type, Int32 depthLimit) at System.Web.Script.Serialization.JavaScriptSerializer.Deserialize[T](String input) at Telerik.Web.UI.RadMultiPage.LoadClientState(String state) at Telerik.Web.UI.RadMultiPage.System.Web.UI.IPostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection) at System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

Please kindly help to resolve this issue ASAP since its a production issue now.

Thanks,
Krishna Samaga B.

Hello Krishna,

This error is most likely caused by malformed data in the POST request. The control failed to deserialize its client state as a result. You should check if your page passes XHTML/HTML validation using either the W3C Validator or a Firefox plug-in like this one.

If your page doesn't have major issues like unclosed tags, etc. we'll need to see a live URL. Alternatively, you can record of the browsing session that reproduces the error using FiddlerCap. Make sure you're not accessing the site through http://localhost, but by using the computer name instead, otherwise it won't capture the traffic.

I hope this helps.

Greetings,
Tsvetomir Tsonev
the Telerik team