I thought it was odd that I was just checking the forum on a laptop and it said I was online, which is weird because I haven't used the forum since I hit a snag recently. And, at that it wasn't logged in so... yeah, probably nothing.

I don't think so. Then it would be a normal 500 error.

At least the website does not use SSL per default (but should, could be abused), the should use HSTS at least.

and check the line above this one
<script async="" src="[url=https://apis.google.com/_/scs/apps-static/_/js/k=oz.gapi.en_US.bQtN8wwm3jw.O/m=plusone/rt=j/sv=1/d=1/ed=1/am=AQ/rs=AGLTcCM3n4Zc-tzXoE3ChmLVEVW6UZtCQQ/t=zcms/cb=gapi.loaded_0"></script&gt]https://apis.google.com/_/scs/apps-static/_/js/k=oz.gapi.en_US.bQtN8wwm3jw.O/m=plusone/rt=j/sv=1/d=1/ed=1/am=AQ/rs=AGLTcCM3n4Zc-tzXoE3ChmLVEVW6UZtCQQ/t=zcms/cb=gapi.loaded_0"></script&gt[/url];

So it is using SSL IIRC....

You can see it via FF and open the inspector in the forum

What do you mean?
No it doesn't ;-)

This is the Google+ API and this is just the dynamically generated DOM ;-)

Or do you see the green SSL label in the address bar on the left side?
Anyway, at least it works now again.

Or do some have still problems?

Out of other threads, seems still to be going on....

You don´t see the ssl-label when opening via CTRL+Shift+I ??????

No not in the address-bar, only via Inspector!

The website does not use SSL when there is no SSL labelat the top.

The external script from Google+ has nothing to do with GOG and is always using SSL if possible, this can be mixed (but mixed content is not good too).

Only account page and all subpages, avatars and forms use SSL, but SSLis not enforced using HSTS.

But that is all not so important.
The login issue seems to be resolved for me and others.

Can you point me to a thread where this exact issue with the 503 error still appears?

funny enough though, in the moment I see a https at the top....but not before....
straaaaaange....

Because you can type https://gog.com/forum and it stays there but from http://gog.com/forum it is not redirected / forced to https://gog.com/forum using HSTS ;-)

So my suggestion would be: please GOG team, use HSTS and enforce SSL / https

Edit: HSTS is a very important option for webservers and can be easily activated by webdevelopers
https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security

Sorry maybe my mistake to not point it out correctly:

The tab I am using here, was before http and suddenly (after posting) went to https ?????

Another tab I have got opened has not changed......despite that I posted there as well....

It seems their sessions expire too fast. I can't stay logged in for more then a couple hours. And that is already for 1 or 2 months. Galaxy client does not have such a problem.

I do not have the problem.

I have looked at the cookies.
login.gog.com has two galaxy-login cookies and both are valid until next year.
The session_gog_com cookie is also valid until January 2016.

So there is no problem (but these values should be much lower).

I am using Google Chrome without extensions.

I had this problem too. About a week ago I decided to try deleting ALL of my gog.com cookies and ensuring that gog.com, www.gog.com and login.gog.com are all configured to allow cookies to be saved (my browser is configured to delete cookies when it closes by default). I logged in after that and since then I haven't needed to log in again.

I'm not sure if cleaning my cookies was necessary, but making sure my browser stored login.gog.com cookies probably was.

Same here, I cleared the website's cache and haven't been logged out since.

I often delete caches, cookies and so on for multiple reasons ;-)
Webdevelopers know that the caches can be very nasty, especially when it comes to outdated JavaScript and so on (FreFox has a very strong cache sometimes).

Manually deleting GOG cookies seems to fixed it for me.