Schedule activation doesn't get upgraded from CQ5.x to AEM 6

Upgrade from CQ5.x to AEM 6.2 or 6.3

Cause

Known issue with Apache Sling.

Resolution

In AEM6.4, a product level fix would be included.  In older versions, follow the steps below:

1. Perform the upgrade of CQ5.x to AEM6 or migration of the content (including /etc/workflow/instances). 
2. Install the attached package fix-sched-activation.zip to the AEM6.2 instance.
3. Log into AEM as admin user.
4. Go to this page /apps/tools/components/fixScheduledWorkflows/run.html.
5. Click start - the tool terminates the old scheduled activations and resubmit them so the scheduled jobs would work.
6. Output would be similar to the sample output below.

If you performed an in-place upgrade, follow these additional steps:

1. Go to http://aem-host:port/crx/explorer/index.jsp
2. Log in as an admin.
3. Open Content Explorer.
4. Browse to /var/eventing/timed-jobs.
5. Right click the timed-jobs node.
6. Select Delete Recursively.
7. Disable Preliminary Scan.
8. Run the deletion.