Verified in Satellite 6.4.2 Snap 1
I kicked off a set of add subscriptions tasks against 30 content hosts.
Then, I killed all dynflow_executor processes
Screenshot 1 shows one of the tasks waiting to be resumed, since dynflow was killed
I then restarted foreman-tasks service and resumed the task.
Screenshot 2 shows the task being resumed.
Screenshot 3 shows the task completing successfully.
Created attachment 1522898 [details]
Created attachment 1522899 [details]
Created attachment 1522900 [details]
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.