Wavelab LE 7 (Mac) and AlertWindow::showMessageBox

Dear Jules, dear all,

We all know that Wavelab is a little bit picky and special as far as VST plugins threads is concerned.

Well, I have a problem that surpasses my level by far. If I release an AlertWindow::showMessageBox dialog box, I am not able to close it, this is, I have to kill the Wavelab app.

Of course, I have tried in both threads: in processing and editor ones. The result is the same.

Does somebody figure out what is happening? Something related with keyboard focus? something related with some kind of modal state of emerging dialog box?

By the way, These dialog boxes work flawlessly in other hosts as Nuendo, Jules’s pluginhost example whithin Mac environment. But also it works in Wavelab for PC!

Thank you,


Wavelab is a strange beast. You’re not running a modal loop, are you? The only safe (well… still not 100% safe) way to show a message box in a plugin is to run it asynchronously.

Jules, does asynchronously mean create another thread exclusively to run the dialog message box(es)?

No! Search the AlertWindow class for “async” and have a read about it. It just means not running a loop on the message thread - you create your modal object and then return control to the normal message loop, rather than waiting for it to be dismissed.

Thank you, Jules! I’ll try it and report it if this is a solution.



Is showMessageBox deprecated in favour of showMessageBoxAsync? The former is not documented anymore, is it?


I’d certainly recommend using the async methods, but haven’t actually deprecated the older methods, which are still useful in some desktop app situations.