Tasks started by trigger based on "Multiple events completed" failing

In certain circumstances a QlikView publisher task started by a trigger based on "Multiple events completed" may fail to be started.

In the QlikView Distribution Root logs the task completion triggers are seen for the triggering tasks:
...
7/16/2018 05:00:00.6101016    Information    Trigger detected. Type=Start, Trigger=ScheduleTrigger, State=2;7/16/2018 5:00:00 AM;Triggered;Unhandled, Task=<task1 name>
7/16/2018 05:00:05.7543472    Information    The task "<task1 name>" finished successfully

7/16/2018 05:26:19.8157391    Information    Trigger detected. Type=Start, Trigger=TaskCompletedTrigger, State=1;7/16/2018 5:26:18 AM;Triggered;Unhandled, Task=<task2 name>
7/16/2018 05:28:20.4672188    Information    The task "<task2 name>" finished successfully
...

However, the dependent task will not start.

Environment:

• QlikView 11.20 SR17

Possible corruption in contents of the Application Data folder.

If it is determined that it is not a "Time constraint" issue, one workaround found is to have the triggering tasks start at different and non-overlapping times. This means that the triggering tasks need to run sequentially and not concurrently.
Another alternative would be to schedule the task instead and create Task Dependencies.
If these methods fail, recreating the QlikView Distribution Service folder may resolve the issue.