In "Preview", I was able to see the image, but somehow after submit it became "not accessible".
2nd try to attach image.

Thank you for update.

Commenting out [NotNull] did make move to next step.
Thank you for this.

My next problem was .NET Framework 4.6.2 installation. I was trying to install runtime version of the .NET
but the version was not visible from project configuration of Visual Studio 2017.
Later I found that it is .NET Framework SDK to be installed.
After installation of the module, now the program compiles and runs as designed.

And the attached is a capture of the 'NotNullAttribute' error message for your reference.



Thank you.

Hello,

this does not happen with the product/project as it is, "out of the box". It looks like that you have referenced, directly or indirectly, the JetBrains.Annotations package.
I suggest to remove that reference.

If you cannot do it for some reason, your other options are:

• Comment out or remove the [NotNull] and [CanBeNull] attributes. They do not affect the program behavior, they are just for analysis.
  
• Use extern aliases to tell the compiler which one of the types you want to use (it doesn't really matter which one, but the compiler needs to have a way to decide). See e.g. stackoverflow.com/questions/3018419/class-with-same-name-in-two-assemblies-intentionally .

Also note that the error message you provided have several typos in it and is not complete. You should copy/paste such information, as the precise and full text is crucial for our analysis.

In addition, that (probably unrelated to this issue), the minimum supported .NET Framework version is 4.6.2. This is also how the project ships. Change the target framework to .NET Framework 4.6.2.

Best regards

Hello OPCLibs,
I am trying to compile Free-trial of "QuickOPC 2018.3" to evaluate and facing an issue as below message :

Compile Error Message :
The type 'NotNullAttribute' exists in both JetBrain.Annotation and OPCLibs.BaseLib .. version = 5.54.453.1 ..."

from "Example for .Net Framework (Source code)" -> C# Examples (Visual Studio) -> WindowService1
-> Service1.Designer.cs -> line number ~ 48
....
[NotNull]
private OpcLabs.EasyOpc.DataAccess.EasyDAClient easyDAClient1 ;
....

My environment is as below :
OS : Window 2016 Server
Visual Studio : 2017 Community
.NET : 4.6.1

Looking forewarding getting solution soon.