java exception?

I got a program working to show info on my draconic reactor. I'm still working on it but every so often I get this and the program stops. I can't figure out the problem or why it's doing it.

Error message:

Java Exception Thrown: Jave.lang.NullPointerException

My code
http://pastebin.com/fDhPGR2Y

It appears that the paste you've linked to has been removed.

Java exceptions indicate a problem has occurred either within ComputerCraft's own code (less likely), or within the code of a third-party peripheral (more likely). That can be because you're calling a function incorrectly (in which case you should still expect to get a more description error), though it's possible you've hit upon a rather more specific bug.

Shot in the dark guess, if your reactor covers multiple chunks then it may relate to those chunks being unloaded sometimes.

ok fixed the pastebin link. Ya its' a draconic reactor multi block and to connect to it got you use the openperipherals. But the thing is I'm right near the chunk as it's only like 3-4 chunks away from my pc so not sure how it gets unloaded.

You'll want to track down the line(s) which're triggering the error, so the first thing to do would be to add a "print(<linenumber>)" before each dreactor or dmon reference.