I am using Abaqus material removal special purpose technique. Verification input file works fine. However I am creating my own input file and getting following error. Elset is defined on line 18 but in error message assembly set is unknown. Does anyone know how this error can be removed?

***ERROR: in keyword *ELEMENTPROGRESSIVEACTIVATION, file "cube_cae_v2.inp", 
line 32: Unknown assembly set SET2
***NOTE: DUE TO AN INPUT ERROR THE ANALYSIS PRE-PROCESSOR HAS BEEN UNABLE TO 
INTERPRET SOME DATA. SUBSEQUENT ERRORS MAY BE CAUSED BY THIS OMISSION

***ERROR: in keyword *INITIALCONDITIONS, file "cube_cae_v2.inp", line 85: 
Unknown assembly element set SET2