# JUCE 9.0.0 : showMessageBoxAsync doesn't work when JUCE\_MODAL\_LOOPS\_PERMITTED=1

**URL:** <https://forum.juce.com/t/juce-9-0-0-showmessageboxasync-doesnt-work-when-juce-modal-loops-permitted-1/69250>\
**Category:** MacOSX and iOS\
**Created:** [August 6, 2026, 2:03pm UTC](https://forum.juce.com/t/juce-9-0-0-showmessageboxasync-doesnt-work-when-juce-modal-loops-permitted-1/69250 "2026-08-06T14:03:05Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![fbecir](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/fbecir/32/12998_2.png) [@fbecir](https://forum.juce.com/u/fbecir)\
**Post date:** [August 6, 2026, 2:03pm UTC](https://forum.juce.com/t/juce-9-0-0-showmessageboxasync-doesnt-work-when-juce-modal-loops-permitted-1/69250/1 "2026-08-06T14:03:05Z")

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Yes I know, JUCE\_MODAL\_LOOPS\_PERMITTED=1 is evil …

With JUCE 8, the following code was working perfectly :

```auto
juce::AlertWindow::showMessageBoxAsync(juce::AlertWindow::InfoIcon, juce::translate("About MyApp"), "message", "OK");

```

Now with JUCE 9, it is still working on Windows and Linux but now on MacOSX the alert window appears during 1 millisecond and disappears …

If JUCE\_MODAL\_LOOPS\_PERMITTED=0, there is no problem (but of course in my project, other problems arise …)

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**Author:** ![anthony-nicholls](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/anthony-nicholls/32/1246_2.png) [@anthony-nicholls](https://forum.juce.com/u/anthony-nicholls)\
**Post date:** [August 6, 2026, 2:15pm UTC](https://forum.juce.com/t/juce-9-0-0-showmessageboxasync-doesnt-work-when-juce-modal-loops-permitted-1/69250/2 "2026-08-06T14:15:16Z")

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I believe this is fixed on the develop branch, this will we released in a 9.0.1 update soon. Please let me know if it’s still not working on the develop branch.

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<div class="post-metadata">

**Author:** ![fbecir](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/fbecir/32/12998_2.png) [@fbecir](https://forum.juce.com/u/fbecir)\
**Post date:** [August 6, 2026, 3:09pm UTC](https://forum.juce.com/t/juce-9-0-0-showmessageboxasync-doesnt-work-when-juce-modal-loops-permitted-1/69250/3 "2026-08-06T15:09:33Z")

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Thanks a lot @anthony-nicholls : it works perfectly with the develop branch.

Problem solved !