AttributeError: ‘M2M100Encoder’ object has no attribute ‘embed_stale’

Why am I performing the operation ‘ct2 transformers converter - model nllb-200-distilled-600M - output dir nllb-200-distilled-600M-CTransllate2’ Reported error: AttributeError: ‘M2M100Encoder’ object has no attribute ‘embed_stale’