I downloaded the "official" Model.xml document
from OMG. The document uses absolute href links to
link between elements. For a variety of reasons,
this file wouldn't import. However, one of the
reasons seems to be that the XMI reader is
treating all links as though they are relative,
even though the links may be absolute. I believe
that the XMI writer needs to test whether or not
the link is absolute before it prepends the base URI.

For example, If you download the file into
directory "E:\test", then the XMI reader will look
for files named 
"file:/E:/test/http://www.omg.org/models/MOF1.4/XMI1.1/Model1.4/PrimitiveTypes.x
ml" instead of going to the url
"http://www.omg.org/models/MOF1.4/XMI1.1/Model1.4/PrimitiveTypes.x
ml". 

Here is the stacktrace:

resolving reference: null,
file:/E:/brian/projects/ssm/build/models/omg/Model.dt
d
org.netbeans.lib.jmi.util.DebugException: no
protocol: /E:/brian/projects/ssm/bu
ild/models/omg/http://www.omg.org/models/MOF1.4/XMI1.1/Model1.4/PrimitiveTypes.x
ml
        at
org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:524)
        at
org.apache.crimson.parser.Parser2.parse(Parser2.java:305)
        at
org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:442)

        at
javax.xml.parsers.SAXParser.parse(SAXParser.java:345)
        at
org.netbeans.lib.jmi.xmi.XmiSAXReader.read(XmiSAXReader.java:99)
        at
org.netbeans.lib.jmi.xmi.XmiSAXReader.read(XmiSAXReader.java:80)
        at
org.netbeans.lib.jmi.xmi.XMISaxReaderImpl.read(XMISaxReaderImpl.java:
78)
        at
org.netbeans.lib.jmi.xmi.XMISaxReaderImpl.read(XMISaxReaderImpl.java:
56)
        at
org.netbeans.modules.mdrexplorer.looks.reflect.actions.LoadXMIAction$
1.run(LoadXMIAction.java:112)
        at org.openide.util.Task.run(Task.java:136)
        at
org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java
:599)
*********** Exception occurred ************ at Fri
Aug 23 02:36:14 CDT 2002
javax.jmi.xmi.MalformedXMIException:
org.netbeans.lib.jmi.util.DebugException: n
o protocol:
/E:/brian/projects/ssm/build/models/omg/http://www.omg.org/models/MO
F1.4/XMI1.1/Model1.4/PrimitiveTypes.xml
        at
org.netbeans.lib.jmi.xmi.XMISaxReaderImpl.read(XMISaxReaderImpl.java:
84)
        at
org.netbeans.lib.jmi.xmi.XMISaxReaderImpl.read(XMISaxReaderImpl.java:
56)
[catch] at
org.netbeans.modules.mdrexplorer.looks.reflect.actions.LoadXMIAction$
1.run(LoadXMIAction.java:112)
        at org.openide.util.Task.run(Task.java:136)
        at
org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java
:599)
java.lang.ClassCastException
        at
org.netbeans.modules.mdrexplorer.looks.MDREventHandler.changeCancelle
d(MDREventHandler.java:142)
        at
org.netbeans.mdr.util.EventNotifier.fireCancelled(EventNotifier.java:
181)
        at
org.netbeans.mdr.util.EventNotifier.fireCancelled(EventNotifier.java:
197)
        at
org.netbeans.mdr.util.TransactionMutex.leave(TransactionMutex.java:16
7)
        at
org.netbeans.mdr.NBMDRepositoryImpl.endTrans(NBMDRepositoryImpl.java:
177)
        at
org.netbeans.modules.mdrexplorer.looks.reflect.actions.LoadXMIAction$
1.run(LoadXMIAction.java:117)
        at org.openide.util.Task.run(Task.java:136)
        at
org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java
:599)
java.lang.Exception: Stack trace
        at
java.lang.Thread.dumpStack(Thread.java:1071)
        at
org.netbeans.mdr.util.TransactionMutex.leave(TransactionMutex.java:16
9)
        at
org.netbeans.mdr.NBMDRepositoryImpl.endTrans(NBMDRepositoryImpl.java:
177)
        at
org.netbeans.modules.mdrexplorer.looks.reflect.actions.LoadXMIAction$
1.run(LoadXMIAction.java:117)
        at org.openide.util.Task.run(Task.java:136)
        at
org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java
:599)
rolled back!