Little precision: when I try to get the worklist item within the corresponding event serial number I got this error: 

26030 Worklist item 19_8 not found for K2:LITWAREINCAdministrator at 10.20.65.130:31

Just a suggestion, you could take a look at the default client event wizard code.  It should have the code bits that you need.

I'm having a very similar issue.  We are using the k2 blackpearl workflow engine and a ASP.NET application.  We have built custom lists to replicate the worklist experience as in the k2 workspace. The problem we are facing is when you redirect an item through the API you cannot open the worklist item anymore.  It gives you the 20630 Worklist item not found error.  any help would be appreciated. thx

have you found a solution to this problem? The code below executes fine, but after the item has been redirected line of code fails with error 20630 worklist item not found for user.

Worklistitem wiClientEvent = wfConnection.OpenWorklistItem(Request.QueryString["SN"].ToString());

I have tried to set the IgnoreStatus parameter to false but it still doesn't work.

Any ideas?

If i understand your post correctly, you are attempting to open the Worklist item after redirecting it. If that is indeed the case, the behaviour is expected. Reasoning:

• 
  
• There is one Worklist item, assigned to User1.
  
• User1 redirects it to User2. Redirect basically "cuts the item and pastes" it in the new user's list. So when User1 attempts to open it after the redirect, it doesn't belong to him/her anymore.