Datasource fails to deploy with an "IllegalArgumentException: Null text" error

ERROR [org.jboss.kernel.plugins.dependency.AbstractKernelController] (main) Error installing to Real: name=vfsfile:/home/aaron/Downloads/jboss-epp-5.1/jboss-as/server/default/deploy/*-ds.xml state=PreReal mode=Manual requiredState=Real
org.jboss.deployers.spi.DeploymentException: Error during deploy: vfsfile:/home/aaron/Downloads/jboss-epp-5.1/jboss-as/server/default/deploy/*-ds.xml
...
Caused by: java.lang.IllegalArgumentException: Null text
     at org.jboss.system.metadata.ServiceTextValueMetaData.setText(ServiceTextValueMetaData.java:94)
     at org.jboss.system.metadata.ServiceTextValueMetaData.<init>(ServiceTextValueMetaData.java:73)
     at org.jboss.resource.deployers.builder.AbstractBuilder.buildSimpleAttribute(AbstractBuilder.java:91)
     at org.jboss.resource.deployers.builder.ManagedConnectionPoolBuilder.buildAttributes(ManagedConnectionPoolBuilder.java:74)
     at org.jboss.resource.deployers.builder.AbstractBuilder.build(AbstractBuilder.java:66)
     at org.jboss.resource.deployers.ManagedConnectionFactoryDeployer.deploy(ManagedConnectionFactoryDeployer.java:177)
     at org.jboss.resource.deployers.ManagedConnectionFactoryDeployer.deploy(ManagedConnectionFactoryDeployer.java:52)
     at org.jboss.deployers.spi.deployer.helpers.AbstractSimpleRealDeployer.internalDeploy(AbstractSimpleRealDeployer.java:62)
     at org.jboss.deployers.spi.deployer.helpers.AbstractRealDeployer.deploy(AbstractRealDeployer.java:55)
     at org.jboss.deployers.plugins.deployers.DeployerWrapper.deploy(DeployerWrapper.java:179)