This is the error I am now receiving after disabling unboxing:

OpcLabs.EasyOpc.OperationModel.OpcException: An OPC operation failure with error ID 'RawEasyDAClient.HResult=0xC004C010' occurred, originating from '' and with depth of 1. The inner exception contains details about the problem. ---> System.TimeoutException: Write not completed. This error indicates that it could not be verified that the requested write operation was completed during the timeout period. It is possible that the write operation will actually succeed or fail, but later. Increase the timeout period if you want to obtain positive or negative indication of the operation outcome. Other reason for this error may be that under heavy loads, topic request or response queue is overflowing. Check the event log for queue overflow errors (if event logging is supported by the product and enabled).
+ The client method called was 'WriteMultipleItemValues'.
--- End of inner exception stack trace ---
at OpcLabs.EasyOpc.Internal.EasyUtilities.CheckSuccess(OperationResult operationResult)
at OpcLabs.EasyOpc.DataAccess.IEasyDAClientExtension.WriteItemValue(IEasyDAClient client, DAItemValueArguments itemValueArguments)
at OpcLabs.EasyOpc.DataAccess.IEasyDAClientExtension.WriteItemValue(IEasyDAClient client, ServerDescriptor serverDescriptor, DAItemDescriptor itemDescriptor, Object value)
at OpcLabs.EasyOpc.DataAccess.IEasyDAClientExtension.WriteItemValue(IEasyDAClient client, String machineName, String serverClass, String itemId, Object value, VarType dataType)
at OpcLabs.EasyOpc.DataAccess.IEasyDAClientExtension.WriteItemValue(IEasyDAClient client, String machineName, String serverClass, String itemId, Object value)

Yes, I'm running the application from VS when it hangs. I will test if it hangs when running the compiled executable. Can I get the workaround for Windows 10.

Thanks.

I have Windows version 20H2, when I tried to run a previously written application that used the EasyDaClient 2018.3 Visual Studio would randomly crash with no indication of the what the problem might be, other than "sometimes" a user access violation occurred message would be displayed - please note I did NOT try to run this application as the problem I was trying to fix was resolved using a computer with an older windows version. I was finally able to conclude that for my development machine I needed the 2020 version of QuickOPC that would support the version of windows I am using and VS no longer crashes on opening. However, now when I try to run my application it hangs if EasyDaClient is added to the solution. I did have the reference to version 5.59.492, but removed that and updated to 5.59.1034, but the application continues to hang if I add an EasyDaClient control, either to the form or dynamically via code. I have gone through my code and commented out line by line, and the EasyDaClient is the only portion that causes the application to hang. There are no error messages/output that I have been able to find and no exceptions thrown. The application just becomes unresponsive.