i have send it to you,please check your email.

i try it again,now,i can connect it without input username ,but when i import node,the problem is still happen.

Exception: Exception of type 'System.Exception' was thrown.
LibUA.MemoryBufferExtensions.Decode (LibUA.Core.MemoryBuffer mem, LibUA.Core.NodeId& id) (at Assets/game4automation/private/Interfaces/OPCUA4Unity/private/LibUA/MemoryBufferExtensions.cs:1865)
LibUA.MemoryBufferExtensions.Decode (LibUA.Core.MemoryBuffer mem, LibUA.Core.ReferenceDescription& rd) (at Assets/game4automation/private/Interfaces/OPCUA4Unity/private/LibUA/MemoryBufferExtensions.cs:1126)
LibUA.Client.Browse (LibUA.Core.BrowseDescription[] requests, System.UInt32 requestedMaxReferencesPerNode, LibUA.Core.BrowseResult[]& results) (at Assets/game4automation/private/Interfaces/OPCUA4Unity/private/LibUA/Client.cs:2795)
game4automation.OPCUA_Interface.ImportNodes (System.String nodeid) (at Assets/game4automation/private/Interfaces/OPCUA4Unity/OPCUA_Interface.cs:289)
game4automation.OPCUA_Interface.ImportNodes () (at Assets/game4automation/private/Interfaces/OPCUA4Unity/OPCUA_Interface.cs:258)
game4automation.OPCUA_Interface.EditorImportNodes () (at Assets/game4automation/private/Interfaces/OPCUA4Unity/OPCUA_Interface.cs:266)
game4automation.OPCUAInterfaceEditor.OnInspectorGUI () (at Assets/game4automation/private/Interfaces/OPCUA4Unity/private/Editor/OPCUAInterfaceEditor.cs:20)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass59_0.b__0 () (at <5b3c67ecf94144358824df756e1fb6eb>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)

if i input the username it will cause this problem.it connect success,but connot import node,as you can see,it just only six node.

this is my opcserver config,i can use opcwatch connect it,it works good.

but if i donot input the username,i canot connect it,the err is like this:

[OPCUA Interface - Connection Error Sequence contains no matching element] 

i have replace the new code whice you sent to me.

but i select only one node, the problem is still happen.my opcserver is prosys, another problem:if i donot input the user and password,i canot connect the server.

i have the same problem,may you send the new code to me?thanks. my email:  maokeuncle@163.com

when i import nodes,it will happen.100%