Sometimes Xcode skipped customModule = "AppName" customModuleProvider = "target"
To fix this, open the storyboard as source code and replace this line:
<viewController storyboardIdentifier="StoryboardId" id="SomeID" customClass="CustomClass" sceneMemberID="viewController">
:
<viewController storyboardIdentifier="StoryboardId" id="SomeID" customClass="CustomClass" customModule="AppName" customModuleProvider="target" sceneMemberID="viewController">
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