I keep getting this when joining Aprilon for some reason.

From the console:
] connect sandbox.aprilon.net
Connecting to sandbox.aprilon.net...
STEAM validation rejected

Any idea what's happening?

I'm getting the same error message sometimes..
My loading always goes stuck at 'Sending Client info...' and I end up pressing cancel.
Then when I try to join again, it says STEAM Validation Rejected, so I join another server ..

I haven't found a fix for this yet, but tell me if you find anything.

Ah yes. This has happened to me a few times.
What I do, is just exit game, sign out of Steam, not exit, then sign back in. That works perfectly for me.

I've seemed to fix this.. But for how long, I don't know Hopefully long cause it never happened before.

Delete of clientregistry.blob and re-install of GMod, and I've not had the problem since.
The only annoying thing now is to regenerate them spawn icons.

Now, find a way for me to join a server with more than 2 people on it!

You need a minimum of 8GB of RAM

I actually do have 8GB RAM. 2x4GB Sticks.

Break them up into 64GB RAM

Do it for science!

I will if you give me £160 to buy the replacements

You mean you bought your MacBook Pro with 8GB of RAM?

Yes, for College I need to virtualise entire computer networks. Domain Controllers, LDAP Servers, File Servers, Web Servers, Database Servers, Firewalls and Clients.

It was much cheaper to do it when I purchased it, rather than buying an upgrade later.

Now that i look more closely, isn't there only 7 black bars on the RAM on image 2?

It is scientifically irrelevant