You should stop the workflow and check:
Delivery parameters Recipients section, by ckicking on the delivery activity from the workflow:
In case of you choose to target your recipients directly in your delivery / delivery template, please check that you have defined the targeted population in the To field (can be undefined only if 1st or 3rd checkboxes are selected).
If all your checks are fine, then please you should submit a ticket on Adobe Campaign support extranet site.
Thank you for the reply. Yes, I have checked those settings, and they are already as you have shown.
Usually this message 'Activity delivery: transition 'Done'; the target activity is not specified' is a warning message, even though it is always better to add an End activity and connect it to the arrow transition outcoming from delivery activity. Otherwise unselect the generate outcoming transition in the delivery activity property of the workflow.
So please correct it to be sure.
Then automatic resuming workflow for delivery is often due to error in delivery itself (it is my usual case, most of all in complex cases of personalisation). Please may you confirm that the delivery logs are all fine ?
If all is fine from delivery logs, I don't see how to help, sorry.
Again, in case of urgent matter for shooting the delivery, please raise a ticket to support.