[1] The planned sequence was as follows:[1] The telemetry of the launcher was lost from about 9 minutes to 9 minutes and 30 seconds (the uncertainty being due to the fact that the data as displayed in real-time may have been extrapolated for a finite amount of time) into the flight, close to the moment when the main stage (EPC) separation and upper stage (ESC-A) ignition should have occurred.

[1] Then about 1 hour after liftoff, Arianespace's CEO and chairman Stéphane Israël made a quick speech saying that the launcher suffered an anomaly.

His statement in front of the VIP audience in the Jupiter control room was: Later in the night, Arianespace issued a first press release [2] mentioning that the Natal tracking station did not acquire telemetry of the launcher, which lasted until the end of the mission, and that the separation of both payloads was confirmed, together with their successful injection into Earth orbit and the link acquisition by both customers.

On the same day, Arianespace issued a second press release[4] stating that SES and YahSat confirmed the acquisition and good health of the two satellites despite a deviation of their trajectory.

[8] The anomaly might have been due to a human error during the programming of the Guidance, Navigation and Control (GNC) combined with a failed verification procedure according to early developments as the launch team reported not to have double-checked the guidance computer parameters to reduce workload duplication, even though double-checking them played the vital role in the rocket's reliability.

The conclusions of the investigation commission led by ESA's inspector general, Toni Tolker-Nielsen, were released on 22 February 2018, indicating that engineers left the inertial navigation units' azimuth value at 90° (the standard for geostationary transfer orbit (GTO) launch on Ariane 5), however unusually 70° was intended for these payloads riding into unusual supersynchronous transfer orbit (GTO), explaining the cause of the 17° trajectory deviation.

[21] SES-14 needed about 4 weeks longer than planned commissioning time, meaning that entry into service now expected in August instead of July.

[26] As of 30 May 2018, Al Yah 3 had arrived to the intended geostationary orbit, after series of recovery maneuvers had been performed and completed its in-orbit testing.