Same problem. Clear your cookies and login state, cache, and maybe offline files... That ended up solving it for me... Also make sure you're using the https sites, as i recall the http one might not honor the cookie you get and keep pestering you log in.

Happening to me too, I'm not logged in according to the bar on the top, but I can still post here. An interesting bug, if nothing else. I'll try clearing cookies and whatnot.

EDIT: Clearing cookies worked (on Chrome at least).

Confirmed: Clearing cookies fixed the login problem for me.

It seems GoG at some point changed its cookies and I also had to allow them for for gog.com, www.gog.com and login.gog.com, whereas gog.com was previously enough.
Clearing the cookies caused it to ask instead of silently fail and this seems to have done the trick.

I think I have also sorted out my cart problem, but it required me to change the webstorage limit for gog from 5MB (!) to 20MB (!!).

The limit was only 1MB a few years ago!

This worked for me as well.

Glad someone stumbled across the Cookie thing!!!

I'm not sure if this works on all browsers, but on Firefox I just searched through the cookies for gog.com, and deleted only those, also cleared my cache (as someone had suggested it) then exited the browser and relaunched. Seems to have fixed it!

I'm having a I guess separate problem with downloads failing 90% of the time on Comcast, but I guess it's unrelated :-/

What browser are you using that it asked you that, out of curiosity? Firefox has an "offline web content and user data" section, but the only sites using it so far are 2 Amazon sites and Bing, using a total 6.7MB.

Still having the problem after clearing cookies and cache.

Mastero_akq gestures at the thread! After a slumber of over 1000 days, it shudders and begins to move!

Just go to the support site next time.

Definitely shudder a bit.

And just be told to reinstall my browser.