Failures when starting background tasks

I am having the UWP application that was converted from Windows Store app. Windows Store app was using ControlChannelTrigger. Now as I am trying to run this app on Windows 10 (converted), I find that background tasks fail to start. I see the following in the event log:

The background task with entry point Background.KATask and name KeepaliveTaskForChannelOne failed to activate with error code 0x8027025A.

The background task with entry point Background.PushNotifyTask and name PushNotificationTaskForChannelOne failed to activate with error code 0x80070057.

and similar.

My background tasks are registered and declared in manifest exactly the same as in ControlChannelTrigger StreamSocket sample in Windows 8 samples collection. What the first code means I have no idea. I know that 0x80070057 is invalid parameter, but what parameter is invalid, again I have no idea.

I googled and found nothing.

So, the question: what should I do to have my background tasks run as specified in Microsoft documentation?

What do these error codes mean in this situation?