(effect) isn't in at least one DRC
ISO IEC 23003-4 (DRC):drcSetEffect: "Specification of metadata sets [...] Required metadata [...] Instructions for one or more DRCs where each DRC has a drcSetEffect field in which the following bits can be set to the value 1 with the restriction that each bit shall be set to the value 1 in at least one of the DRCs: (1-based) Bit position 1 (“Late night” effect), Bit position 2 (“Noisy environment” effect), Bit position 3 (“Limited Playback Range” effect), Bit position 6 (“General compression” effect)"
ISO IEC 23003-4:
Fix the encoder in order to set at least 1 instance of (effect) in drcInstructions, then reencode the content.