Ok, I have a simple test environment. From C#, using OPC UA, I can read DINTs, write DINTs, read Structs, but when I try to write a struct I get BadNotWritable. I am using Communication Manager, OPC UA Server, and IEC Symbol Publishing. I have a struct defined with one single DINT in it. The instance of the struct is in GVL. The struct is marked read/write in IEC Symbol Publishing. Any ideas? Pointers are welcome. public static async Task WriteStructA(byte[] structAData) { if (_session == null) throw...