Hi,
did you mean ICMR = Input Common Mode Range?
If so: In an closed loop opamp circuit both In- an In+ have (about) the same voltage. The allowed voltage range at these inputs is ICMR.
Design your application that both inputs are in the allowed voltage range.
If you run the opamp with one or both inputs outside tihis range the circuit may not work like specified. Saturation may occur, phase reversal may occur, latch up with its latch_up_time may occur.
Increased supply current, and and and.
Make sure to avoid this situation.