Formatting string with %@ in Swift

You neglected to provide any details about the crash but one obvious problem is the use of the %@ format specifier with an Int. You need to use %d with Int.

You need to replace %@ with %d. ImageCount is Int value. so use %d instead of %@.

Format specifier:

%d - int Value 
%f - float value
%ld - long value
%@ - string value and for many more.

For see all Format Specifiers see Apple Doc Format Specifiers