I also encountered this on Ubuntu 14.04.1. I had to rebuild the server from source. I think that it wants the stdc++ libs to match the ones that it was compiled with.
I can't understand why people use ubuntu instead of Debian for servers... does it have some advantage or something?
I don't actually use Ubuntu for serving. I just use it for the interface when developing plugins. Having the console and your text editor side-by-side is really convienient. I usually use headless Debian for the serious server stuff.
I had this problem on Ubuntu 14.04 as well, just install g++ 4.9 and it should work.
i had on my server ubuntu, too. MCServer had the same error and i had installed g++. Now i am using debian and installed everthing without problems. They are only some bugs with mobs

That has nothing to do with the OS though, they are just not fully implemented yet
