You must have Votifier and Vote listener. If your using Hosting company to host your server, Contact their support and ask, if they even allow Votifier connections. If this didn't help, be sure to check out Youtube. There is loads of Minecraft plugin guides.
Check your Java version. Uninstall your older java, and go Download newest version. If this didn't work, Force-update your Minecraft, so open your Minecraft launcher, options, Force-update, ok and login.
Force update your Minecraft. If that still doesn't make sense, just wait patiently. Check if your server plugins are oudated, just open command prompt and type in reload, and check if there is any errors. Minecraft 1.4.2 may still be full of bugs.
Out of memory means, your computer has too low amount of RAM. You must buy better Desktop/Laptop[I recommend Desktop], or buy more RAM for your Computer.