Hello, Mark,

I have tested with the latest version and when the UseSystemPasswordChar property is set to true and the content in RadTextBoxControl is selected, the keys combination Ctrl+C doesn't perform copy operation on my end. If you try pasting after that in Notepad for example, you will notice that the last copied content is pasted. 

I have attached my sample project. Please give it a try and see how it works on your end. Am I missing something? Could you please specify the exact steps how to reproduce the problem? Thank you in advance. 

I am looking forward to your reply.

Regards,
Dess | Tech Support Engineer, Principal
Progress Telerik

Hello, Damien,

The fix about this issue was introduced in our latest R3 2020 (version 2020.3.915). Could you please make sure that you refer to dlls from the latest version in your project. Sometimes, after an upgrade, the GAC folder may have more that one version. Please refer to the following help article on how to examine the GAC and ensure that there is just the latest version: https://docs.telerik.com/devtools/winforms/knowledge-base/examine-the-gac 

You should carefully check the references to all Telerik controls in your project and make sure that they are the same version considering the suffix as well (.20 or .40). Better yet, you can remove all references and add them anew by using the DLLs from your fresh installation. Delete the license.licx file. After that, you should rebuild your project, close Visual Studio, and open it again to make sure that no references are kept in the memory by Visual Studio.

I hope this information helps.

Regards,
Nadya
Progress Telerik

Hello,

A workaround, until the issue is fixed, would be to disable the context menu in the text field and to clear the clipboard on KeyDown event, when Ctrl+X and Ctrl+C are used.

Regards,
Stoyan
Progress Telerik