I've found an issue with MediaEmbed option and Youtube links embeding.
On the 0.1.4 version (which was the last version before upgrading my forum) all Youtube videos are embedding just fine, but since updating to 1.0.2 most of them reporting a "video unavailable" error.
This one doesn't work:
But this one loads just fine:
More links with "video unavailable" error:
https://youtu.be/k03HK88HhmU
https://youtu.be/0zGcUoRlhmw
https://youtu.be/dE-nP1KsaBo
https://youtu.be/HxsNy4NoZUs
More working links:
https://youtu.be/1OrNS2zbTZg
https://youtu.be/hVwtC8X7NC4
https://youtu.be/sTxzmLyVFYY
https://youtu.be/cMOAXm94VWo
EDIT:
The difference between working and non-working links is that non-working videos have some kind of a Licence added. But at the same time, they are all working on the previous version of the extension, as well as on the other places (tested on Facebook, Twitter...)