I encountered this issue via Admin API. I found that when I deployed a VDB with View DDL definition I sometimes was not able to retrieve the VDB via the Admin API getVDBs method.

Steps to reproduce:

1) Deploy VDB with a valid JDBC source. works OK.

2) now, Add a View DDL defn to the VDB and redeploy it. For valid View DDL that references the JDBC source defined in 1), this works fine.

However, if I submit DDL that is a valid query - but references a non-existent source group - I get the following exceptions in the log

15:57:13,993 INFO [org.jboss.as.server.deployment] (MSC service thread 1-7) JBAS015876: Starting deployment of "MyVDB-vdb.xml"
15:57:14,026 INFO [org.jboss.as.osgi] (MSC service thread 1-5) JBAS011907: Register module: Module "deployment.MyVDB-vdb.xml:main" from Service Module Loader
15:57:14,031 INFO [org.teiid.RUNTIME] (MSC service thread 1-5) TEIID50029 VDB MyVDB.1 model "testJDBCModel" metadata is currently being loaded. Start Time: 7/13/12 3:57 PM
15:57:14,031 INFO [org.teiid.RUNTIME] (MSC service thread 1-5) TEIID50029 VDB MyVDB.1 model "MyViewModel" metadata is currently being loaded. Start Time: 7/13/12 3:57 PM
15:57:14,056 INFO [org.teiid.RUNTIME] (teiid-async-threads - 2) TEIID50030 VDB MyVDB.1 model "testJDBCModel" metadata loaded. End Time: 7/13/12 3:57 PM
15:57:14,109 INFO [org.teiid.RUNTIME] (teiid-async-threads - 3) TEIID50030 VDB MyVDB.1 model "MyViewModel" metadata loaded. End Time: 7/13/12 3:57 PM
15:57:14,136 INFO [org.jboss.as.server] (management-handler-thread - 5) JBAS018559: Deployed "MyVDB-vdb.xml"
15:57:14,144 WARN [org.teiid.PLANNER.RESOLVER] (teiid-async-threads - 3) TEIID31080 View MyViewModel.SFAccountBillingView validation error: QueryResolverException-Group does not exist: testSalesforceModel.Account
15:57:14,145 WARN [org.teiid.PLANNER.RESOLVER] (teiid-async-threads - 3) TEIID31071 Invalid table; Table SFAccountBillingView has no columns defined
15:57:14,146 INFO [org.teiid.RUNTIME] (teiid-async-threads - 3) TEIID40073 The metadata for the VDB MyVDB.1 is loaded, however it is not valid. Check models for errors. Correct the metadata and re-deploy.
16:00:22,351 INFO [org.jboss.as.connector.subsystems.datasources] (MSC service thread 1-4) JBAS010400: Bound data source [java:/MyVDB]

After the above submittal of view DDL that references a non-existent source - the admin.getVDBs() call doesnt return anything. Normally I'd get the VDBMetaData, make changes and redeploy. But in this case, I do not get the previously deployed VDB.