Event Object Missing

I just assembled a Prusa Mendel, sprinter, running on Pronterface and was having some trouble with the extruder. I took it off and cleaned it and what not, and now when hit the extrude button on pronterface I get the message "event object missing". What does this mean?

just guessing here but i think it needs a value ...to the right of the extrude button you need to type in an amount ( in mm) for it to extude

It (the value) is set, it just doesn't work.

so youve got pronterface to connect to your machine and can control the XYZ axes ?
you need to set the hot end temp and wait for it to reach the temp before it will extrude. If you press "extrude" before then you should get the message " cold extrusion prevented" in the terminal window. do you get that??
( the value below which it will not extrude is set in the config.h file)

You might try posting your question in the firmware section on the forum where hopefully someone with more firmware knowledge than me may be able to help

Good luck