Crash at [NSMutableAttributedString(NSMutableAttributedStringKitAdditions) fixFontAttributeInRange:]

Hi, I am setting the attributed string to NSTextStorage and replacing it with another attributed string if need changes. I am getting crash with this stack trace:

  • CoreFoundation CFCharacterSetIsLongCharacterMember + 0x28
  • UIFoundation -[NSMutableAttributedString(NSMutableAttributedStringKitAdditions) fixFontAttributeInRange:] + 0x15fc
  • UIFoundation -[NSMutableAttributedString(NSMutableAttributedStringKitAdditions) fixAttributesInRange:] + 0x70
  • UIFoundation -[NSTextStorage processEditing] + 0xe0
  • UIFoundation -[NSTextStorage edited:range:changeInLength:] + 0x14c
  • Foundation -[NSConcreteMutableAttributedString replaceCharactersInRange:withAttributedString:] + 0x158
  • UIFoundation __71-[NSConcreteTextStorage replaceCharactersInRange:withAttributedString:]_block_invoke + 0x28
  • UIFoundation __NSConcreteTextStorageLockedForwarding + 0x34
  • UIFoundation -[NSConcreteTextStorage replaceCharactersInRange:withAttributedString:] + 0x44 \

Please help with what could be the issue. I have checked that the attributed string is not nil and the font is UIFont *.