The mscorlib.dll throws the above exception when adding objects to a hashtable. This is despite the code being within a synclock statement. My understanding is that the error is a thread issue and should be prevented by Synclock statements. The code is unchanged so it should not have stopped working. Does anybody know of any known bugs or possible explanations? Below is an example of the code. Note that MyBase refers to a hashtable as the class is inherited from one.

SyncLock MyBase.SyncRoot
  try
     MyBase.Add(NewBusinessObject.UniqueID, NewBusinessObject)
     Catch e As Exception
         Throw exception
  End Try
End SyncLock

Apologies. It was not a bug after all, but a genuine duplicate in the hash table caused by rogue data.

Hi

I am getting the Similar error
will you please help me in C#

here is the error
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Item has already been added. Key in dictionary: "en-GB" Key being added: "en-GB"
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentException: Item has already been added. Key in dictionary: "en-GB" Key being added: "en-GB"

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[ArgumentException: Item has already been added. Key in dictionary: "en-GB" Key being added: "en-GB"]
   System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean add) +955
   System.Collections.Hashtable.Add(Object key, Object value) +11
   System.Resources.ResourceManager.InternalGetResour ceSet(CultureInfo culture, Boolean createIfNotExists, Boolean tryParents) +571
   System.Resources.ResourceManager.GetString(String name, CultureInfo culture) +103
   System.Web.HttpRuntime.GetResourceStringFromResour ceManager(String key) +184
   System.Web.UI.WebControls.BaseValidator.RegisterVa lidatorCommonScript() +127
   System.Web.UI.WebControls.BaseValidator.OnPreRende r(EventArgs e) +44
   System.Web.UI.Control.PreRenderRecursiveInternal() +62
   System.Web.UI.Control.PreRenderRecursiveInternal() +125
   System.Web.UI.Control.PreRenderRecursiveInternal() +125
   System.Web.UI.Control.PreRenderRecursiveInternal() +125
   System.Web.UI.Control.PreRenderRecursiveInternal() +125
   System.Web.UI.Control.PreRenderRecursiveInternal() +125
   System.Web.UI.Control.PreRenderRecursiveInternal() +125
   System.Web.UI.Page.ProcessRequestMain() +1476




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Regards
SRee

A curve that can set lot of things i.e Smile