Undefined variable kN.m

Lex Martinez wrote: yes I type dot between two units, I also tried to do it in other computer the result are the same undefined variable for kN.m. Why the software can able to read kg.m2/s2 instead of kN.m ?

Not sure what the problem is, you will have to show a worksheet.

You can assign a variable the unit kg.m2/s2 or the unit kN.m. In both a cases, when you evaluate that variable you will see the resullt expressed in unit Joule.

There are some options you may change in the Math tab, icon units:

The unit system (usually SI, I guess) and if you want the results expressed in base units only (which should be off normally)

With SI-units and base units off you will see Joule in the above example. If you turn on base units you will see kg.m2/s2 (Joule is not a base unit). If you want to see kN.m you will have to type them yourself replacing the unit Prime has offered. You may type kN alone and Prime will add the necessary m itself (in front of the kN, though, making m.kN)

In MC15 we had the choice of user units or change the units displayed (so you get kN.m instead of J automatically) by fumbling around in the configuration files. I am not sure if this still applies to Prime.