'Mi' is not a subtype of type 'IF' with dart2js


I’m facing an issue with dart2js since today, dart2js go to the end without any error, but when i launch my webapp on a browser (Chrome) the console send this error “Uncaught type ‘Mi’ is not a subtype of type ‘IF’ “
But when running on Dartium, there is no bug. I’m not really into JavaScript, so i don’t know how to investigate further.

My app is deployed there :
And the page with the bug is :

My sources are on Github here :

Thanks in advance 😀


When I’m running it in Dartium it does cause an exception too.

In your jeu.html you have

<input id="nextPageButton" type="button"/>

And in your main.dart you have:

ButtonElement b = querySelector("#nextPageButton");

And so the error message in Dart is:

Exception: type 'InputElement' is not a subtype of type 'ButtonElement' of 'b'.

Either use a button-tag in your html or an InputElement in your main.dart to fix this issue.

Answered By – Dennis Kaselow

Answer Checked By – Marilyn (FlutterFixes Volunteer)

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