CookieContainer.Add Method (Cookie)
Assembly: System (in System.dll)
cookie is a null reference (Nothing in Visual Basic).
The domain for cookie is a null reference (Nothing in Visual Basic) or the empty string ("").
cookie is larger than maxCookieSize.
the domain for cookie is not a valid URI.
If the Count property equals or exceeds the Capacity property, one or more Cookie instances are removed from the container before adding the cookie parameter. Enough Cookie instances are removed to bring Count below Capacity as follows: if there are expired instances in the given scope, they are cleaned up. If not, then the least recently used CookieCollection is found and removed from the container.