Scheduler issues ("DeleteBySelection" operation failed / Automatic trigger not launch / Manual reload from QMC show only Triggered status)

[mickael_b2boost]

Hello community,

I have a global issue that seems link to the scheduler. 

One task is "blocked" in reload status for more than one week. This task can't be aborted, or deleted. When I try to delete the task, this message appears : "DeleteBySelection" operation failed

The related app can be reloaded manually from the hub, but can't be deleted from hub or qmc. On log I can see this message when trying to delete the app : Bad Request [400]:Bad Request(Object write failed.) (HTTP code: 400)

When I change the app used in the reload of the task with issue for an other app, I can delete the app but not the new one used.

It seems this have impact on others tasks : Scheduled tasks don't work anymore, and when I launch a reload manually from the QMC, only the status Triggered is shown (even if the task is successfully reloaded). After relaunching services, the good status is shown (success)

I try to perform server update, from February 2021 to August 2021, because a bug with same error message was corrected on this version, but it doesn't help. It's like the scheduler service doesn't work anymore. Services can be restarted without any issues.

Do you have any idea how to resolve that? I can't find any information about this error message except something link to stream but here it's at task level, not stream.

Thank you very much for your help,

Mickael

[mickael_b2boost · Accepted solution]

Solution provided by Qlik support following this article : https://community.qlik.com/t5/Official-Support-Articles/Qlik-Sense-Scheduler-Tasks-keep-failing-Post...
One entry on ExecutionSessions table in Qlik PostgreSQL DB had blank appid.

Thank you very much.