Computercraft solar panel script java exception not attatched to this computer

I am using a Lua script to manage my solar panels. But for some reason after a certain amount of time, I get this java exception after X amount of time using the script. The solar panels are located in an always day mystcraft world. I am not sure if this happens when I load the world. Im playing on a self hosted direwolf 1.10.0 server minecraft version 1.7.10. The versions of my peripheral mods are found in the gyazo and the computer craft version is 1.75. Can anyone help me with this?

p = peripheral.wrap("back") 
function Solar() os.sleep(4) if p.getEnergyStored() > 5800000 then
   while p.getEnergyStored() > 600000 do redstone.setOutput("back",true) os.sleep(4) end
   redstone.setOutput("back",false) else redstone.setOutput("back",false) end end 
while true do Solar() end

https://gyazo.com/faabde4a9cfe1533ac30258a6fc00081
https://gyazo.com/3a7204ce7e7a1c7b1d5a8448846abffa