Hello,
I have the same error message as the description but I am not using code behind, or client API, or any other special feature, this is happening in a simple process where I reject an approval and return the flow to a previous step with a value of "Rejected" then in the previous step the user should have to modify the request and send it again to the approval, when the user hits the Submit button the form throw the infopath error dialog but anyway the form closes and the process continue successfully, But, I get this error on the ULS. The weird thing here is that using the InfoPath client this does not occurs. Do you have some clue about this error?.
2. 26030 Worklist item [serialNumer] not found for K2: [domain][user] at [ipAddress]:[port]
This error typically indicates that there are no slots available. While the user does have access to the worklist item, it has been opened by one or more users and all slots have been consumed.
When writing custom code using the Workflow Client API that deals with worklist items, it is good practice to check the Status property (use the WorklistStatus enumeration) of the WorklistItem object before attempting to open it. If the status is “Allocated”, meaning the worklist item is allocated to other users, you will not be able to open it.
This error will also occur when attempting to open a worklist item using an invalid serial number.
