I encountered a problem when adding a new custom font in Xcode 16.1. After including the font and opening my XIB files, the interface preview became blank and the application seemed to experience a heavy load.
To troubleshoot, I removed all custom fonts, and everything returned to normal functionality. However, even after reinstalling Xcode, the issue persisted when adding the font again.
The XIB preview loaded correctly:
The XIB preview turned blank and became unresponsive: