I am having the same issue as this thread here : SPListDataValidationException in an event receiver on a task list with Overdue tasks.
When I use
item.Update();, an exception is thrown "The following error occurred: Microsoft.SharePoint.SPListDataValidationException: List data validation failed. ".
Now I would like to disable the column validation before the item update and then re-enable it after the update.
Is this possible? I cannot find any useful documentation in msdn.