There are two issues here at play that interact to a crash. First is using sender() inside the slot of a single shot connection. This doesn't work reliably as inside doActivate the connection is removed before invoking the slot. However QObject::sender() will look through all connections to find one with the same sender as the currentSender otherwise it returns nullptr. Which means as long as there are other connections to the same object sender() would still work. This brings us to the second issue, if the model changes between modelAboutToBeReset and modelReset, down the line the signal from the old model would still be handled and since there were no other connections to the old model anymore crash. Pick-to: 6.7 Change-Id: I71af46ec691e0c130cf367ac9fa04308c0826481 Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>