BrowseNodeExample chokes on ObjectType (expecting Object)

[Yes293p]

I am new to the project, so I am sorry if this is an ignorant question, but I am trying to browse nodes using these nice examples, and I run into exceptions like this (there are actually roughly 4000 lines of similar printed to the console). I wonder if there's some type checking I could do to avoid this.

08:43:45.002 [milo-shared-thread-pool-1] WARN o.e.m.opcua.sdk.client.AddressSpace - Failed to create Node from Reference to ExpandedNodeId{ns=0, id=2318, serverIndex=0} java.util.concurrent.CompletionException: UaException: status=Bad_UnexpectedError, message=java.lang.IllegalArgumentException: expected NodeClass.Object, got NodeClass.ObjectType at java.base/java.util.concurrent.CompletableFuture.encodeRelay(CompletableFuture.java:368) at java.base/java.util.concurrent.CompletableFuture.completeRelay(CompletableFuture.java:377) at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1152) at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510) at java.base/java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:2147) at org.eclipse.milo.opcua.stack.client.UaStackClient.lambda$deliverResponse$5(UaStackClient.java:318) at org.eclipse.milo.opcua.stack.core.util.ExecutionQueue$InlineTask.run(ExecutionQueue.java:154) at org.eclipse.milo.opcua.stack.core.util.ExecutionQueue$Task.run(ExecutionQueue.java:136) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) at java.base/java.lang.Thread.run(Thread.java:840) Caused by: org.eclipse.milo.opcua.stack.core.UaException: java.lang.IllegalArgumentException: expected NodeClass.Object, got NodeClass.ObjectType at org.eclipse.milo.opcua.sdk.client.AddressSpace.newObjectNode(AddressSpace.java:1243) at org.eclipse.milo.opcua.sdk.client.AddressSpace.lambda$getObjectNodeAsync$2(AddressSpace.java:215) at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1150) ... 8 common frames omitted

[kevinherron]

What server are you browsing against? Typically when I've seen this it's because the Server address space is put together incorrectly. It may help if you can provide the full log export and a Wireshark capture.

[Yes293p]

Thanks Kevin for the very quick and useful response. I will see if I can introspect this Server to see why that may the case. I am browsing a commercial server, and I'm not sure what documentation may be proprietary so I will check first before giving more details, but this certainly helps me to move forward. Meanwhile, I am having fun getting more familiar with the powerful milo SDK. Thanks again!

[kevinherron]

This is strictly an invalid address space and non-compliant behavior from the server, so the only really work around you have on the client side is to not use the versions of browse that return Nodes; stick to the ones that return ReferenceDescriptions. And then presumably don't trust the NodeClass indicated in the ReferenceDescription.

[Yes293p]

FWIW here is the documentation for the server: https://d3.cytivalifesciences.com/prod/IFU/29752660.pdf (From https://www.cytivalifesciences.com/en/us/search#q=unicorn%20opc%20server&t=coveo5819fbca)

[kevinherron]

I have seen that name come up with our support department a couple times. I don't think it's a very good piece of software, or at least its OPC UA interface.

If you are a paying customer you should report bugs like this to them.

[Yes293p]

Thanks again. When I browse using a GUI Client (UA Expert), I see what I think are the offending nodes: HA Configuration nodes which do show up on this client as ObjectType but with EventNotifier listed as having invalid attribute. I will indeed follow up with the makers of the server.

Meanwhile your suggestion as a workaround is fruitful. In particular BrowseExample seems to work despite these server issues.