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ReadMultipleValues exception

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support
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29 Jan 2020 15:15 #8178 by support

Replied by support on topic ReadMultipleValues exception

Hello,

have you regenerated the unit files for the QuickOPC assemblies from the new type libraries (see documentation)?

Best regards

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Boris
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29 Jan 2020 15:05 #8177 by Boris

ReadMultipleValues exception was created by Boris

Hello!

I'm using Delphi XE8. I tried to upgrade from version 2018.3 (5.54.1281.1) to version 2019.2 (5.56.475.1). Immediately after the update, a critical error occurred while executing the ReadMultipleValues function.The error occurs only when reading a tag with data type "18 [ExpandedNodeId]" from the UA AnsiC Demo Server (I did not test with other UA servers).
The problem is easy to reproduce using your demo project "..\OPC Labs QuickOPC 2019.2\Examples-COM\OP\UADocExamples\_EasyUAClient\ReadMultipleValues.Main.inc". You need to take this example and change part of the code, like this:

ReadArguments3 := CoUAReadArguments.Create;
ReadArguments3.EndpointDescriptor.UrlString := 'opc.tcp://PC_NAME:48020';  // AnciC UA Demo Server
ReadArguments3.NodeDescriptor.NodeId.ExpandedText := 'ns=4;s=Demo.Dynamic.Scalar.ExpandedNodeId';

Now this project will always end with an error of EAccessViolation.
In the old version, this error does not occur.