IEditableTextControl will not accept text

I have a user reporting that the text box on my plugin (IEditableTextControl) will not accept text - either by pasting in or typing in. They sent a screen video showing the situation. He clicks on the field and the textbox opens - then tries to paste or type something in and it stays blank (text format is black on white background).

The text box works perfectly for me on all platforms, DAWs and OS - and no other user has ever reported such a problem - so I am assuming this is specific to one user’s computer.

Anyone have any possible idea what could be causing this? Antivirus or form blocker of some sort perhaps?

It’s possible the host is intercepting keystrokes - there are a couple of issues on GitHub about this sort of thing - worth checking the format (I think this affects VSTs only - not sure if that is VST2 and VST3 or just the former).

Thank you for the reply - I will check GitHub.

The DAW he is using is Reaper on Win10. He said he tried it on another DAW and it did the same thing. I asked if he tried it on another computer and he has not replied to that question.

I suspect there is a keylogger, form blocker or some other security software on his PC - or perhaps a virus. I have never had any reports of this problem from anyone else. I cannot reproduce it here on any DAW or plugin format on any OS, Mac or PC.

I did not ask if he tried both VST and VST3 - I will - but I suspect he will get the same result.

Just curious if anyone here has come across this.

BTW - the text box he is trying to access is our license code entry box. I hate to make assumptions but perhaps he is trying to glean information about how our license system works. He has asked for a second code to “try”.