Hello. I use X5 in Windows 11. I don't have this problem.

Try uninstalling the program, download this https://helpcenter.websitex5.com/en/community/users/880449/downloads and install again.

Try not to run any other programs, try temporarily disabling your antivirus and firewall (for experimentation).

Also You can try this https://computerinfobits.com/how-to-force-quit-on-windows/#force-close-an-application-using-windows-task-manager

Hi Aleksej H, thank you for your suggestions. I appreciate you taking the time to respond to me.

I have already uninstalled and then reinstalled the latest version. Unfortunately this did not solve the problem.

I tried temporarily disabling my antivirus programs, Malwarebytes and Bitdefender, but it didn't solve the problem. As an aside, while looking at the logs of my antivirus programs I found that Malwarebytes quaranteened C:\DOCUMENTS AND SETTINGS\Desktop\WebsiteX5 Pro.lnk as it identified it as ransomware (see attached jpg).

Using the Windows task manager to force close the application does work, but it is only a quick and nasty fix and obviously doesn't address whatever is the the underlying issue.

Hello. I sent a notification about your question to the company employees, expect an answer from them here in the comments.

Hello Robert

Could it be that Malwarebytes had already quarantined the WebSite X5 file prior to your test?

The fact that there's no way to stop the software from running via the X button usually means that software operativity is being interfered with by a different software. I don't think I received other similar reports of such an issue with older versions of Windows nor Windows 11.

If you try to disable that software, then install the software anew and retry, does the issue persist?

I remain available here

Stefano

Hello, Robert:
The .lnk extension is for shortcuts that are placed on the desktop. Well, some need administrator credentials.

1) Have you already deleted the desktop shortcut, before reinstalling the program? (Which brings me to the next question...)
2) Did you download the setup file from here from the incomedia site? From your answer to Aleksej I will assume yes...
3) Can't reverse the quarantine in the antivirus?
4) Does your windows user account have administrator rights?

If this is the case that your account is not an administrator and the program was installed by the administrator, it is likely that you will not be able to run it correctly (in your case close it), I am going to assume, hypothetically, that the antivirus takes as access unauthorized access to the administrator account and takes it as an attack, forcing it to shut down abruptly. Which an administrator would realize that someone tried to use a program to which he is not authorized. It's a hypothesis xD

Administrator privileges. I think is the problem.

If you previously installed the program as administrator and you are running it with an account without administrator rights, and you did not give yourself permission to use the program, it will show problems.
If you later deleted the program as a non-rights user, control remains with the main administrator.

I hope you understand what I'm trying to say. And let this be the problem and not a real virus.

Greetings.