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tristaanogre
7 years agoEsteemed Contributor
TC 14 lists QT support up through version 5.9 of QT. I don't know what the maximum version for 12.20 is but it could be possible that you're using a version of QT that is outside of this scope.
Additionally, there is a specific set of components that are supported. See
One last check... go to File | Install Extensions and expand the Desktop support. There should be options there for QT Application and QT Controls. Make sure both are checked.