[Superllama12]

We have had issues like this from last year and this one. We discovered that it is very easy to mess up a terminator and/or CAN cables. One way to check this (though you may have already) is to check each individual cable with a multimeter, along with the terminator. If that doesn't work, open the jags and check inside for dust or metal shavings, those messed up ours a lot last year. Use a pneumatic hose to blow the gunk off. Lastly, are you connecting to the computer using jag--serial, or jag--serial--USB? Ours will not allow us to use USB because we were using a school desktop computer, which requires admin log-in to use, but works fine for serial. Anyways, good luck, and I hope you find the solution!