If you are having problems following other users on SoundCloud, it may be for a few different reasons:
 

You’ve hit the 2000 following limit

The overall limit is 2000 and applies to all subscriptions. This is a measure designed to reduce stability issues related to following a large number of accounts (e.g., problems loading your Stream, following page, etc.). 
 

You’ve been put in a temporary block 

There are currently limits on the number of follow actions you can make within 24 hours and on re-following the same accounts within a short period.

If you are repeatedly flagged for these kinds of activities it’s possible that your account will be temporarily blocked from following or unfollowing any more accounts. The duration of these blocks will increase in length each subsequent time you hit these limits.

Please understand that these limits are in place to address community complaints about accounts overusing features or using them in ways other than intended. 
 

422 - Unprocessable entity error 

If you’re having issues following or unfollowing users and you haven’t hit any of these limits, it’s possible you might be experiencing a known caching issue on the platform. Usually, if this is the case, you will see a message reading “422 - unprocessable entity” when attempting a follow-up action. 

Here is how you can work around this until this is fixed:

• Choose any other user profile and start following the user.
• Briefly afterward, unfollow that user again to trigger the cache to be reset.
• Now go back to the user profile that was giving you the error message. From there, you should be able to follow or unfollow as usual.