Ensure the total size matches the expected layer (likely a BD-25 or part of a BD-50 set).

While is a specific episode of the acclaimed BBC crime drama, the addition of the BDMV keyword typically refers to a specific Blu-ray file format often sought by collectors or those managing high-definition home media libraries. What is Shetland Season 5, Episode 4?

suggests you want episode 4 in full Blu-ray quality (not a compressed 1GB TV rip, but a 15-25GB+ file with original bitrate).