Getting an error when trying a simple Domain Class

[gkrasnow]

| Error 2012-12-11 14:41:49,349 [http-bio-8090-exec-10] ERROR errors.GrailsExceptionResolver - IllegalStateException occurred when processing request: [POST] /VektorServices/classB/save - parameters:
b: dfgdfdsf
create: Create
Method on class [mongotest.ClassB] was used outside of a Grails application. If running in the context of a test using the mocking API or bootstrap Grails correctly.. Stacktrace follows:
Message: Method on class [mongotest.ClassB] was used outside of a Grails application. If running in the context of a test using the mocking API or bootstrap Grails correctly.
Line | Method
->> 134 | doCall in grails.plugins.mongodb.MongoPluginSupport$_addInstanceMethods_closure3

---

| 24 | save in mongotest.ClassBController
| 195 | doFilter . . . . in grails.plugin.cache.web.filter.PageFragmentCachingFilter
| 63 | doFilter in grails.plugin.cache.web.filter.AbstractFilter
| 46 | doFilterInternal in org.grails.jaxrs.web.JaxrsFilter
| 886 | runTask in java.util.concurrent.ThreadPoolExecutor$Worker
| 908 | run . . . . . . in ''
^ 680 | run in java.lang.Thread

package mongotest

import com.google.code.morphia.annotations.Entity
import grails.plugins.mongodb.ast.TransformationConfiguration
import com.google.code.morphia.annotations.Reference

@Entity
@TransformationConfiguration(injectId = true)
class ClassA {
    String foo
    Integer bar

    @Reference
    ClassB b

    Date dateCreated
    Date lastUpdated

    static constraints = {
    }
}

package mongotest

import com.google.code.morphia.annotations.Entity
import grails.plugins.mongodb.ast.TransformationConfiguration

@Entity
@TransformationConfiguration(injectId = true)
class ClassB {
    String b
    Date dateCreated
    Date lastUpdated

    static constraints = {
        b nullable: false
    }
}