Protect against a lack of metadata.

                throw new IllegalArgumentException("Owner is not a condition provider service");

            }

            final int ruleInstanceLimit = owner.metaData.getInt(

            int ruleInstanceLimit = -1;

            if (owner.metaData != null) {

                ruleInstanceLimit = owner.metaData.getInt(

                        ConditionProviderService.META_DATA_RULE_INSTANCE_LIMIT, -1);

            }

            if (ruleInstanceLimit > 0 && ruleInstanceLimit

                    < (getCurrentInstanceCount(automaticZenRule.getOwner()) + 1)) {

                throw new IllegalArgumentException("Rule instance limit exceeded");