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MOST COMMON: If youtube is the only encode missing, then an issue exists with the youtube version of the file. If the file hasn't shown up as a "youtube duplicate", then reading of the youtube logs might be appropriate to glean further knowledge. It's possible that the file is a duplicate, but the status is not catching. You can check for logs on Splunk for prod-edx-veda index to understand where the code broke.
II. "My whole course isn't completed"
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