This can be reproduce on all platforms

Reproduce steps:'
1. download the test.zip I attached and unzip it.
2. cd to test
3. set JAVAHOME to a valid jdk build.


4. execute
${JAVA_HOME}/bin/idlj -fall -i/${JAVA_HOME}/include -pkgPrefix CosTransactions org.omg test.idl

5. compile all the java files. Given test.zip is extracted to a local dir "./test"

${JAVA_HOME}/bin/javac --add-modules java.corba,jdk.rmic -nowarn -g -d ./workdir -classpath "./workdir" --add-exports java.corba/com.sun.corba.se.spi.activation=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.spi.activation.LocatorPackage=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.spi.ior=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.spi.ior.iiop=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.impl.orbutil=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.spi.protocol=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.impl.oa.poa=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.spi.orb=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.spi.transport=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.spi.legacy.connection=ALL-UNNAMED --add-exports java.corba/com.sun.corba.se.impl.legacy.connection=ALL-UNNAMED ./test/product/orbspi/customsocket/*.java

6.mkdir repository_4050

7. register orbd. "-d64" is only for 64 bit JVM.
${JAVA_HOME}/bin/java -d64 -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 -classpath "./" -XaddExports:java.corba/com.sun.corba.se.spi.activation,java.corba/com.sun.corba.se.spi.activation.LocatorPackage,java.corba/com.sun.corba.se.spi.ior,java.corba/com.sun.corba.se.spi.ior.iiop,java.corba/com.sun.corba.se.impl.orbutil,java.corba/com.sun.corba.se.spi.protocol,java.corba/com.sun.corba.se.impl.oa.poa,java.corba/com.sun.corba.se.spi.orb,java.corba/com.sun.corba.se.spi.transport,java.corba/com.sun.corba.se.spi.legacy.connection,java.corba/com.sun.corba.se.impl.legacy.connection \
-Dcom.sun.CORBA.POA.ORBBadServerIdHandlerClass=product.orbspi.customsocket.BadServerIdHandlerImpl \
-Dcom.sun.CORBA.connection.ORBSocketFactoryClass=product.orbspi.customsocket.CustomSocketFactory \
com.sun.corba.se.impl.activation.ORBD -port 4049 -defaultdb ./repository_4050 -ORBInitialPort 4050 -ORBInitialHost localhost -serverPollingTime 50 -serverStartupDelay 200 -ORBDebug orbd &

8. start the server endpoint
${JAVA_HOME}/bin/java --add-modules java.corba,jdk.rmic com.sun.corba.se.impl.activation.ServerTool -ORBInitialPort 4050 -cmd \
register -server product.orbspi.customsocket.Server \
-applicationName customSocket \
-classpath "./workdir" \
-vmargs -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 \
-DIORdir=./workdir/product/orbspi/customsocket \
-args persistent

9. run client. This can be ignored now since the test failed at step 8.
${JAVA_HOME}//bin/java -d64 -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 -classpath "./" -XaddExports:java.corba/com.sun.corba.se.spi.activation,java.corba/com.sun.corba.se.spi.activation.LocatorPackage,java.corba/com.sun.corba.se.spi.ior,java.corba/com.sun.corba.se.spi.ior.iiop,java.corba/com.sun.corba.se.impl.orbutil,java.corba/com.sun.corba.se.spi.protocol,java.corba/com.sun.corba.se.impl.oa.poa,java.corba/com.sun.corba.se.spi.orb,java.corba/com.sun.corba.se.spi.transport,java.corba/com.sun.corba.se.spi.legacy.connection,java.corba/com.sun.corba.se.impl.legacy.connection -DIORdir=./product/orbspi/customsocket \
-DUseOnlyTaggedComponents=true \
-Dcom.sun.CORBA.connection.ORBSocketFactoryClass=product.orbspi.customsocket.CustomSocketFactory \
product.orbspi.customsocket.Client persistent


Expected: the server should run successfully at step 8. But it failed immediately with main class not found.
ServerTableEntry constructed with activation command C:\Users\aurora\CommonData\jdk\bin\java -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket -Dioser=null -Dorg.omg.CORBA.ORBInitialPort=4050 -Dcom.sun.CORBA.activation.DbDir= -Dcom.sun.CORBA.POA.ORBActivated=true -Dcom.sun.CORBA.POA.ORBServerId=-1 -Dcom.sun.CORBA.POA.ORBServerName=product.orbspi.customsocket.Server -Dcom.sun.CORBA.activation.ORBServerVerify=true -classpath ./workdir;./workdir com.sun.corba.se.impl.activation.ServerMain persistent -debug
Server being verified w/C:\Users\aurora\CommonData\jdk\bin\java -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket -Dioser=null -Dorg.omg.CORBA.ORBInitialPort=4050 -Dcom.sun.CORBA.activation.DbDir= -Dcom.sun.CORBA.POA.ORBActivated=true -Dcom.sun.CORBA.POA.ORBServerId=-1 -Dcom.sun.CORBA.POA.ORBServerName=product.orbspi.customsocket.Server -Dcom.sun.CORBA.activation.ORBServerVerify=true -classpath ./workdir;./workdir com.sun.corba.se.impl.activation.ServerMain persistent -debug
ServerTableEntry: method =verify
ServerTableEntry: server =-1
ServerTableEntry: state =ACTIVATING
ServerTableEntry: message =returns main class not found

Bad server definition: main class not found.

================
I suppose it is because java.corba is not in root modules of server app and com.sun.corba.se.impl.activation are not exported.

So try with following:
C:/Users/aurora/CommonData/jdk/bin/java --add-modules java.corba,jdk.rmic com.sun.corba.se.impl.activation.ServerTool -ORBInitialPort 4050 -cmd register -server product.orbspi.customsocket.Server -applicationName customSocket -classpath "./workdir" -vmargs --add-modules java.corba,jdk.rmic --add-exports java.corba/com.sun.corba.se.impl.activation=ALL-UNNAMED -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket -args persistent

ServerTableEntry constructed with activation command C:\Users\aurora\CommonData\jdk\bin\java --add-modules java.corba,jdk.rmic --add-exports java.corba/com.sun.corba.se.impl.activation=ALL-UNNAMED -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket -Dioser=null -Dorg.omg.CORBA.ORBInitialPort=4050 -Dcom.sun.CORBA.activation.DbDir= -Dcom.sun.CORBA.POA.ORBActivated=true -Dcom.sun.CORBA.POA.ORBServerId=-1 -Dcom.sun.CORBA.POA.ORBServerName=product.orbspi.customsocket.Server -Dcom.sun.CORBA.activation.ORBServerVerify=true -classpath ./workdir;./workdir com.sun.corba.se.impl.activation.ServerMain persistent -debug
Server being verified w/C:\Users\aurora\CommonData\jdk\bin\java --add-modules java.corba,jdk.rmic --add-exports java.corba/com.sun.corba.se.impl.activation=ALL-UNNAMED -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket -Dioser=null -Dorg.omg.CORBA.ORBInitialPort=4050 -Dcom.sun.CORBA.activation.DbDir= -Dcom.sun.CORBA.POA.ORBActivated=true -Dcom.sun.CORBA.POA.ORBServerId=-1 -Dcom.sun.CORBA.POA.ORBServerName=product.orbspi.customsocket.Server -Dcom.sun.CORBA.activation.ORBServerVerify=true -classpath ./workdir;./workdir com.sun.corba.se.impl.activation.ServerMain persistent -debug
ServerTableEntry: method =verify
ServerTableEntry: server =-1
ServerTableEntry: state =ACTIVATING
ServerTableEntry: message =returns Server terminated normally

RepositoryImpl: registerServer called to register ServerDef ServerDef[applicationName=customSocket serverName=product.orbspi.customsocket.Server serverClassPath=./workdir serverArgs=persistent serverVmArgs=--add-modules java.corba,jdk.rmic --add-exports java.corba/com.sun.corba.se.impl.activation=ALL-UNNAMED -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket] with new serverId 257
ServerManagerImpl: getEntry: no active server found.
RepositoryImpl: getServer for serverId 257 returns ServerDef[applicationName=customSocket serverName=product.orbspi.customsocket.Server serverClassPath=./workdir serverArgs=persistent serverVmArgs=--add-modules java.corba,jdk.rmic --add-exports java.corba/com.sun.corba.se.impl.activation=ALL-UNNAMED -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket]
ServerTableEntry constructed with activation command C:\Users\aurora\CommonData\jdk\bin\java --add-modules java.corba,jdk.rmic --add-exports java.corba/com.sun.corba.se.impl.activation=ALL-UNNAMED -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 -DIORdir=./workdir/javahome/product/orbspi/customsocket -Dioser=null -Dorg.omg.CORBA.ORBInitialPort=4050 -Dcom.sun.CORBA.activation.DbDir=C:\Users\aurora\.\repository_4050 -Dcom.sun.CORBA.POA.ORBActivated=true -Dcom.sun.CORBA.POA.ORBServerId=257 -Dcom.sun.CORBA.POA.ORBServerName=product.orbspi.customsocket.Server -classpath ./workdir;./workdir com.sun.corba.se.impl.activation.ServerMain persistent -debug
ServerTableEntry: method =activate
ServerTableEntry: server =257
ServerTableEntry: state =ACTIVATED
ServerTableEntry: message =activating server

ServerManagerImpl: locateServer called with serverId=257 endpointType=IIOP_CLEAR_TEXT block=false
ServerManagerImpl: activate for server Id 257 found location null and activated it
ServerManagerImpl: getEntry: active server found ServerTableEntry[state=ACTIVATED serverId=257 activateRetryCount=0].
ServerManagerImpl: active for server Id 257 called. This server is now active.
ServerTableEntry: method =register
ServerTableEntry: server =257
ServerTableEntry: state =ACTIVATED
ServerTableEntry: message =process registered back

ServerManagerImpl: registerEndpoints for server Id 257 called. This server is now active.
registering type: IIOP_CLEAR_TEXT port 51110
ServerTableEntry: method =registerPorts
ServerTableEntry: server =257
ServerTableEntry: state =RUNNING
ServerTableEntry: message =process registered Ports

lookup num-ports 1 IIOP_CLEAR_TEXT 51110
ServerTableEntry: method =deActivate
ServerTableEntry: server =257
ServerTableEntry: state =DE_ACTIVATED
ServerTableEntry: message =server deactivated

org.omg.CORBA.COMM_FAILURE: ----------BEGIN server-side stack trace----------
org.omg.CORBA.COMM_FAILURE: vmcid: SUN minor code: 208 completed: Maybe
        at java.corba@9-ea/com.sun.corba.se.impl.logging.ORBUtilSystemException.connectionAbort(ORBUtilSystemException.java:2400)
        at java.corba@9-ea/com.sun.corba.se.impl.logging.ORBUtilSystemException.connectionAbort(ORBUtilSystemException.java:2418)
        at java.corba@9-ea/com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.readBits(SocketOrChannelConnectionImpl.java:375)
        at java.corba@9-ea/com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.handleEvent(SocketOrChannelConnectionImpl.java:1148)
        at java.corba@9-ea/com.sun.corba.se.impl.transport.SelectorImpl.run(SelectorImpl.java:324)
Caused by: org.omg.CORBA.COMM_FAILURE: vmcid: SUN minor code: 211 completed: No
        at java.corba@9-ea/com.sun.corba.se.impl.logging.ORBUtilSystemException.ioexceptionWhenReadingConnection(ORBUtilSystemException.java:2484)
        at java.corba@9-ea/com.sun.corba.se.impl.logging.ORBUtilSystemException.ioexceptionWhenReadingConnection(ORBUtilSystemException.java:2502)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.giopmsgheaders.MessageBase.readGIOPHeader(MessageBase.java:134)
        at java.corba@9-ea/com.sun.corba.se.impl.transport.CorbaContactInfoBase.createMessageMediator(CorbaContactInfoBase.java:168)
        at java.corba@9-ea/com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.readBits(SocketOrChannelConnectionImpl.java:333)
        ... 2 more
Caused by: java.io.IOException: An existing connection was forcibly closed by the remote host
        at java.base/sun.nio.ch.SocketDispatcher.read0(Native Method)
        at java.base/sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
        at java.base/sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
        at java.base/sun.nio.ch.IOUtil.read(IOUtil.java:192)
        at java.base/sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:382)
        at java.corba@9-ea/com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.readFully(SocketOrChannelConnectionImpl.java:620)
        at java.corba@9-ea/com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.read(SocketOrChannelConnectionImpl.java:542)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.giopmsgheaders.MessageBase.readGIOPHeader(MessageBase.java:130)
        ... 4 more

----------END server-side stack trace---------- vmcid: SUN minor code: 208 completed: Maybe
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:461)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.giopmsgheaders.MessageBase.getSystemException(MessageBase.java:921)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.giopmsgheaders.ReplyMessage_1_2.getSystemException(ReplyMessage_1_2.java:116)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaMessageMediatorImpl.getSystemExceptionReply(CorbaMessageMediatorImpl.java:590)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientRequestDispatcherImpl.processResponse(CorbaClientRequestDispatcherImpl.java:489)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientRequestDispatcherImpl.marshalingComplete(CorbaClientRequestDispatcherImpl.java:373)
        at java.corba@9-ea/com.sun.corba.se.impl.protocol.CorbaClientDelegateImpl.invoke(CorbaClientDelegateImpl.java:148)
        at java.corba@9-ea/org.omg.CORBA.portable.ObjectImpl._invoke(ObjectImpl.java:475)
        at java.corba@9-ea/com.sun.corba.se.spi.activation._ActivatorStub.install(_ActivatorStub.java:152)
        at java.corba@9-ea/com.sun.corba.se.impl.activation.RegisterServer.processCommand(ServerTool.java:333)
        at java.corba@9-ea/com.sun.corba.se.impl.activation.ServerTool.executeCommand(ServerTool.java:209)
        at java.corba@9-ea/com.sun.corba.se.impl.activation.ServerTool.run(ServerTool.java:95)
        at java.corba@9-ea/com.sun.corba.se.impl.activation.ServerTool.main(ServerTool.java:122)


==============================================
This was a success history output on Windows:
ServerTableEntry: method =activate
ServerTableEntry: server =257
ServerTableEntry: state =ACTIVATED
ServerTableEntry: message =activating server

ServerManagerImpl: locateServer called with serverId=257 endpointType=IIOP_CLEAR_TEXT block=false
ServerManagerImpl: activate for server Id 257 found location null and activated it
ServerManagerImpl: getEntry: active server found ServerTableEntry[state=ACTIVATED serverId=257 activateRetryCount=0].
ServerManagerImpl: active for server Id 257 called. This server is now active.
ServerTableEntry: method =register
ServerTableEntry: server =257
ServerTableEntry: state =ACTIVATED
ServerTableEntry: message =process registered back

ServerManagerImpl: registerEndpoints for server Id 257 called. This server is now active.
registering type: IIOP_CLEAR_TEXT port 64921
ServerTableEntry: method =registerPorts
ServerTableEntry: server =257
ServerTableEntry: state =RUNNING
ServerTableEntry: message =process registered Ports

lookup num-ports 1 IIOP_CLEAR_TEXT 64921

Then at step 9, client/server communicates successfully. Please refer to the sample output:
Initialized the ORB
Read the IOR from the file
Invoking echo() operation...
CLIENT: received msg. from Server: Hello Client
CLIENT: received msg. from Server: Hello Client
CLIENT: received msg. from Server: Hello Client