Task Execute operation 'syncPanelsWithConfiguration' with ID $CONFIGURATION_UID on resource $PANEL_UID" fails with the following output:
"Internal Server Error: Apply configuration for some Plesks has been failed. Details: Subscription:  Plesk in VPS VPS name: server-12345678-1 Plesk Panel uid: 63c69ab4-52a9-4d29-b2e5-3a4c412fb478 Error: Specified resource `63c69ab4-52a9-4d29-b2e5-3a4c412fb478` is not found." }
Subscription was cancelled or expired after the configuration changes were applied. Subscriptions are non-existent on OA side anymore.
Task could be safely cancelled, since it is related only to the mentioned subscription, which does not exist anymore.