Hi,

We are aware of some issues. They usually happen if the NamespaceArray of the server lacks mappings or there is set of “empty” namespaces having empty string or null as their uri. We’ll try to fix these in future versions. Note that the changes between 3.x and 4.x basically makes them 2 separate applications.

For 4.x you can check if the logs show the error just in case it was not covered by above situations, see logs in folder /.prosysopc/prosys-opc-ua-browser/log