Model number 30TSPTN

I have 4 of these lifts, 2 of them shut off while up in the air. The one today shut off, we used the manual valve to lower it. I plugged in my service terminal, and got a code for Service 42. The chain is not broken, but the chain service light is on? Please help, this lift is blocking an aisle and i need to get it going.

Sorry to edit, Just a little background, i am a military mechanic with zero training on these. everything i have learned, i taught myself from the book in the last 3 months.

Thank you