Soundcloud API upload stopped working - soundcloud

Question

I've run the following code for over a year and it suddenly stopped working. It has worked until 5/19/2016, and it started failing on 5/31/2016.
import soundcloud
client = soundcloud.Client(access_token=params['token'])
track_uri = client.get('/tracks/' + str(track_id)).uri # This works
client.put(track_uri, track=track) # This fails
It gives me the following traceback:
Traceback (most recent call last):
File "./tools/upload_track.py", line 56, in <module>
client.put(track_uri, track=track)
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/soundcloud/client.py", line 133, in _request
return wrapped_resource(make_request(method, url, kwargs))
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/soundcloud/request.py", line 148, in make_request
result.raise_for_status()
File "/Library/Python/2.7/site-packages/requests/models.py", line 844, in raise_for_status
raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 401 Client Error: Unauthorized for url: https://api.soundcloud.com/tracks/266983865
It turns out that despite the error my track is uploaded to Soundcloud anyway. Unfortunately I can't ignore the error because in some cases I post new tracks (client.post instead of client.put), and I need to know the track_id's in order to put them into a playlist.
Some of the things I've tried, where I got the same error:
I tried uploading to a different Soundcloud account
I tried creating the client object with client_id, client_secret, username, and password instead of access_token
I double checked that the token is valid, that it's different every time I run the code, and that the client.get call fails when I use the wrong token