The probably cause of this problem is that you don't have the license (option) for multiple systems. Abacus requires a license in order to run tests on more than 1 Abacus Systems. If you don't have that, you will get a compilation error when starting a test. You may get to System Information --> Connected Systems, highlight the SC and check in the "options" window to see if you have the "Multi System"option checked. This option is needed for each and every Abacus System included in your test.
If you don't see the option checked and want to run test on multiple systems, please contact your Spirent Account Manager.