open the Info.plist in its editor, by selecting Info.plist in the Navigator on the left. You'll find that the width of the Key field has been made very wide, and this is tied to the width of the Key field in the Info panel.
If you can't see the column width handles in the Info.plist editor, you can scroll the whole display to the left to bring them into view. The Target's Info tab editor can't do that.
Topic:
Developer Tools & Services
SubTopic:
Xcode
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