Can't login or access web app. How do I fix proxy and firewall blocking access to Spotify? Error 30

[FJ123]

When I try to access the Spotify Web App it says a firewall or proxy is blocking it. 

When I try and access the Spotify Desktop app it won't let me login, quotes error code 30, citing a proxy issue and won't let me login. 

Spotify does work on my android phone and I have deduced that the issue must be proxy and / or firewall related.

I have tried removing and then adding Chrome and Spotify from my firewall. 

I have no idea what to change in proxy settings, I have looked at some tutorials but they make little sense. 

I am running a 2015 Macbook Pro with Mojave, 10.14.6. 

Please help! This issue has been ongoing for months. I have now found the time to try and remedy the issue but have found little to no help online or from Spotify. 

Thanks.

[Mario]

Hey @FJ123,

Welcome to the Spotify Community and thanks for reaching out about this here. 
 
It'd be great to try some more trouble-shooting and see whether performing a clean reinstall of the app on your MacBook does the trick in this situation.
 
You can follow the steps featured in this Spotify Answer to try with this procedure.
 
Let us know how you get on. We'll look out for your reply!

[FJ123]

Thanks for getting back to me.

I have tried that multiple times but to no avail. I am me with 'a firewall may be blocking Spotify. Please update your firewall to allow Spotify. Additionally you could try changing the currently used proxy settings. (Error Code: Auth:3). 

Prior to the clean reinstall I was logged into Spotify but music wouldn't play. I could click on an artist or song but the song wouldn't load or progress through the track. I don't know if perhaps the issues are related and my proxy settings are blocking Spotify from doing its thing?