It appears to be an issue with the /v2/subjects endpoint that is failing to respond after the first page of results. I expect Tofugu are probably on it fixing this, but just wanted to make it clear this is effecting everything, from individual apps, to the WaniKani Open Framework that many userscripts rely on.
Just making a post to make this clear as I’m seeing a lot of posts across my app, as well as Tsurukame and Jakeipuu 
Well, it’s nearly 2AM here in the UK, so I’m heading to bed.
I HEARBY ALLOW ANY REGULARS OR @MODS TO CHANGE THE TITLE SHOULD THE ISSUE BE RESOLVED
Just so nobody gets confused unduly ^^
Thanks for notifying of this error. I was wondering why Tsurukame stopped working for me this morning (8am JST)
JST here. I’ll try to keep an eye on the forum and redirect people here whenever I see something 
I just noticed no sound is playing on my Tsurukame app. Is this caused by the API glitch?
The error message states:
“Error playing audio
You do not have permission to access
URL: https://files.wanikani.com/ ayzv8gkbaan09fo28a5mjrqru054”
Very likely yes. The audio is fetched during the review. It looks like an authentication issue related to the API.
Tip: You can pre-download the audios in the Tsurukame settings (I don’t think it will work now, but keep it in mind for the future 
)
Just fyi, it looks like the API is working again.
Hey everyone! This issue should be fixed now. If you continue to notice anything awry, please let me know so we can take a closer look.
I noticed that the WaniKanify extension is no longer working for me. Is anyone else having this problem?
Audio is fixed on Tsurukame! Thanks team!
Thank you! Back to being able to log in and use Tsurukame
Reported 7hours ago, fixed 4 hours ago.
Nice! (Both sides)
Smouldering Durtles seems to be syncing now. Hopefully it will sync and I can continue on as I was on FD.
I deployed this lovely workaround to my code yesterday, I guess that’s related to this issue, and I can remove it again now?
res = requests.get(next_url.replace("www.", "api."), headers=headers)
Yep, that’s what they fixed.