There are similar issues with Swat, season 1 episodes 21 and 22 for myself. Where on all devices I receive the something went wrong error message. Couldn't even download them on my iPad.
Decided to go onto Live chat and explain the situation, where I was transferred to level 2 for technical support. Who then told me there is a known issue across other episodes.
It might be best to on Live chat and let them know what you are having issues with.
1. NOW TV account & payments
2. Cancelling or renewing NOW TV Passes
3. Drop down 'How to get in touch'
4. Live Chat
FYI that I do not work for NOW, just a NOW customer trying to help