This generation glitch/oversight still exists in the 1.9 snapshots.
If this isn't a bug, then its definitely a feature of the generation engine that could use a tweak. Like I said earlier, the land underneath almost every river rises above the river level at some point, cutting it off. It looks unrealistic and rather ugly to me. Looking at the screenshots I posted, I'm sure you'd agree with me. If the developers have marked this as WAI (which I don't necessarily think they have, MC-53767 looks like a custom world) then I think it's at least a much-needed tweak to the world generation system. The ideal river for me would be one that you could sail on from one ocean to another.
I just don't believe the developers intentionally wanted the land level in river biomes to frequently rise above the sea level, creating dry portions of rivers.
This was fixed in 1.6.4 (I think). But there is still a way to X-Ray.
You have to delete your map. Sorry for this.
It could be that you use Java 32-Bit and/or a 32-Bit Operating System. 32-Bit Systems/Programs can only use 2GB of RAM maximum, so it gives you an error saying "Could not create Java Virtual Machine.".
If not this, then your whole Operating System will probably crash if you only have 2GB of RAM. (Basically, if you have 2GB of RAM, don't allocate your whole system amount, in your case 2GB) All the best,
TheTechGamer4321 🙂
Ummm... How do I post a screenshot of the title screen?
That could just be the Texture/Resorce pack that you're using.
Added screenshots from version 16w02a.