This looks to be introduced in JDK 9 b155. I attached source codes to reproduce the failures. Reproducible on all platforms.

Reproduce steps:
1. compile the codes with javac
2. generate tie files as following
/path-to-jdk-9/bin/rmic -classpath . -iiop -keepgenerated -d . ProcessorImpl LegacyProcessorServer
3. start tnameserv
/path-to-jdk-9/bin/tnameserv.exe -ORBInitialPort 4050 &
4. Launch the server side
/path-to-jdk-9/bin/java -Dsun.reflect.debugModuleAccessChecks --add-modules java.corba,jdk.rmic -Dsun.reflect.enableModuleChecks=debug -Dorg.omg.CORBA.ORBInitialPort=4050 -Dorg.omg.CORBA.ORBInitialHost=localhost -Dorg.omg.CORBA.ORBClass=com.sun.corba.se.impl.orb.ORBImpl -Dorg.omg.CORBA.ORBSingletonClass=com.sun.corba.se.impl.orb.ORBSingleton -Djava.naming.factory.initial=com.sun.jndi.cosnaming.CNCtxFactory -Djava.naming.provider.url=iiop://localhost:4050 -classpath "./" --add-exports jdk.rmic/sun.tools.java=ALL-UNNAMED LegacyProcessorServer sun_orb &

5. Run client side:
/path-to-jdk-9/bin/java -Dsun.reflect.debugModuleAccessChecks --add-modules java.corba,jdk.rmic -Dsun.reflect.enableModuleChecks=debug -Dorg.omg.CORBA.ORBInitialPort=4050 -Dorg.omg.CORBA.ORBInitialHost=localhost -Dorg.omg.CORBA.ORBClass=com.sun.corba.se.impl.orb.ORBImpl -Dorg.omg.CORBA.ORBSingletonClass=com.sun.corba.se.impl.orb.ORBSingleton -Djava.naming.factory.initial=com.sun.jndi.cosnaming.CNCtxFactory -Djava.naming.provider.url=iiop://localhost:4050 -classpath . --add-exports jdk.rmic/sun.tools.java=ALL-UNNAMED Client "corbaname:iiop:1.2@localhost:4050#sun_orb" IIOPProcessorFactory


Expected: it passed all tests.
Actually: all failed.
Detail stacktraces as below:
---------------------------------------------
Executing Test: testRuntimeException
RuntimeException reason string is not expected:
org.omg.CORBA.UNKNOWN: vmcid: 0x0 minor code: 0 completed: Maybe
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.UEInfoServiceCont
ext.<init>(UEInfoServiceContext.java:52)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInsta
nce0(Native Method)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInsta
nce(NativeConstructorAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newI
nstance(DelegatingConstructorAccessorImpl.java:45)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:
466)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContextDat
a.makeServiceContext(ServiceContextData.java:132)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContexts.u
nmarshal(ServiceContexts.java:216)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContexts.g
et(ServiceContexts.java:378)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContexts.g
et(ServiceContexts.java:366)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientRequestDisp
atcherImpl.processResponse(CorbaClientRequestDispatcherImpl.java:530)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientRequestDisp
atcherImpl.marshalingComplete(CorbaClientRequestDispatcherImpl.java:373)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientDelegateImp
l.invoke(CorbaClientDelegateImpl.java:148)
        at java.corba@9-ea/org.omg.CORBA.portable.ObjectImpl._invoke(ObjectImpl.
java:475)
        at _ProcessorInterface_Stub.testRuntimeException(Unknown Source)
        at TesterImpl.testRuntimeException(TesterImpl.java:65)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Nativ
e Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Native
MethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(De
legatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:543)
        at TesterImpl.performTests(TesterImpl.java:34)
        at Client.main(Client.java:37)
Unexpected InvocationTargetException:
java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Nativ
e Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Native
MethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(De
legatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:543)
        at TesterImpl.performTests(TesterImpl.java:34)
        at Client.main(Client.java:37)
Caused by: java.lang.RuntimeException: Bad reason string: []
        at TesterImpl.testRuntimeException(TesterImpl.java:71)
        ... 6 more

---------------------------------------------
Executing Test: testRemoteException
Unexpected InvocationTargetException:
java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Nativ
e Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Native
MethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(De
legatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:543)
        at TesterImpl.performTests(TesterImpl.java:34)
        at Client.main(Client.java:37)
Caused by: org.omg.CORBA.UNKNOWN: vmcid: 0x0 minor code: 0 completed: Maybe
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.UEInfoServiceCont
ext.<init>(UEInfoServiceContext.java:52)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInsta
nce0(Native Method)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInsta
nce(NativeConstructorAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newI
nstance(DelegatingConstructorAccessorImpl.java:45)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:
466)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContextDat
a.makeServiceContext(ServiceContextData.java:132)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContexts.u
nmarshal(ServiceContexts.java:216)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContexts.g
et(ServiceContexts.java:378)
        at java.corba@9-ea/com.sun.corba.se.spi.servicecontext.ServiceContexts.g
et(ServiceContexts.java:366)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientRequestDisp
atcherImpl.processResponse(CorbaClientRequestDispatcherImpl.java:530)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientRequestDisp
atcherImpl.marshalingComplete(CorbaClientRequestDispatcherImpl.java:373)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientDelegateImp
l.invoke(CorbaClientDelegateImpl.java:148)
        at java.corba@9-ea/org.omg.CORBA.portable.ObjectImpl._invoke(ObjectImpl.
java:475)
        at _ProcessorInterface_Stub.testRemoteException(Unknown Source)
        at TesterImpl.testRemoteException(TesterImpl.java:84)
        ... 6 more
Exception in thread "main" java.lang.RuntimeException: 2 unexpected failures
        at Client.main(Client.java:42)