Having the same issue with the latest version 3 (Windows 10). Can't connect to Soundcloud anymore.
This worked for me:
I usually start S1 as an administrator (due to JBridged plugins). Now it shows that this is actually causing the issue with the soundcloud client.
As soon as I start S1 as a normal user, the connection process just works fine and you can restart S1 as an admin again.
I hope, I can help someone with this information.