Event: 151 - Task Scheduler failed to instantiate task at service startup. Task instantiation failed "Task Name". Check point: Load-CompareHash. Error Value: 2147750689.
and
Event ID: 101 - Task Start Failed Task Scheduler failed to start "Task Name" task for user "computername\username". Additional Data: Error Value: 2147750689.
These errors started to appear after I changed the password of the user running that task. The task still did what it was suppose to do, but the errors annoyed me. I first reset the password again, then deleted and re-added the task, the problem persisted. During troubleshooting I managed to get rid of the errors and got a warning instead:
NewInstanceIgnored Event ID: 322 - Task: Launch request ignored, instance already running Level: Warning Task Scheduler did not launch task "Task Name" because instance " 73E2A202-35D9-4D81-AD8B-51B374A02DCE}" of the same task is already running.
Which was not true and after re-adding the task I got the two errors back.
I then created a new task with a different name but using the exact same properties and the same user.
That task works without problems and throws no warnings or errors.
So I decided to give up on finding out where whose errors came from, I disabled the original tasks and was about to close the issue.
Well, guess what I am still getting the errors in the event log even though that task is no scheduled to run.
So I deleted the task completely to finally get rid of the errors.
Not so fast Sherlock! they still kept coming even though I could find any trace of the mentioned task on the machine anymore.
Nothing when using the GUI, schtasks.exe or in 'C:\Windows\System32\Tasks'
It refused to die and keep coming back to haunt me.
A reboot of the server finally put the task to rest.
This all happened on Windows Server 2012 core.