Generated when the value of the MonomialOrder option is not compatible with a specification of elimination variables.
Elimination variables are specified in the third argument of GroebnerBasis, the fourth argument of PolynomialReduce, or the third argument of GroebnerBasis`DistributedTermsList.
Off[message] switches off the message; On[message] switches it on. For example: Off[GroebnerBasis::elmvar].