Weird phenomenon - cancelled flights?

I have a flight map created, and I got a message saying this:

Flight #1 has been cancelled

2017-12-29 00:00 HT

Due to one of the following reasons, we were not able to complete fight number 1 :

The aircraft does not have sufficient flight or cabin crew assigned.

The aircraft was not located at the departure airport.

The aircraft requires technical maintenance.

The flight had accumulated excessive delay.

The affected aircraft is C-ACJG. If the flight is still listed in the flight plan, you may review it at the following location: Flight #1.

Sincerely, your Flight Planning Department.

I have enough cabin crew assigned, I know that for sure. The aircraft was located at the departure airport, Calgary (YYC), the condition of the aircraft is 94% but I’m not too sure about the excessive delay. What might have caused this?

go to the "flights" tab of that aircraft and hover your mouse over the "delay code" (the two letters). will give you the actual reason