Out of memory although you still have enough ram?

I have assigned Minecraft 2 GB Ram. I have 4 GB Ram installed and 2.4 of them are free. Why am I then displayed as an error message out of memory?

Because Minecraft wants more than just 2GB, but does not have it and should not take it on a 4GB system.

I also tried 1GB, still does not work, although it has worked half a year ago?

If it does not work with 2 GB, why should it work with 1 GB?

Why does not it generally work with 1 GB although it worked 6 months ago? Counter questions also do not help me much…

Nh. Maybe something has changed in the settings or the world in which you play, needs a lot of power.

Minecraft never needs more than 700MB in Vanilla, unless there's much more available.

Maybe the new version is too much for your PC?

Yes no. I can't even get into the main menu: /

Into the launcher do you mean?

Main menu is main menu and not launcher lol

Then it may need to be more than allocated for starting, e.g. For loading worlds / texturepacks / mods