@jeffleeismyhero could you add some steps to reproduce? Can I reproduce it in the current demo? Would be nice so we can add some unit tests for unit.

It seems like the select field buttons were modified in d06d8a9. I was working on version 3.12.0. Since those buttons are no longer present, this isn't a problem --- for the iPad idiom.

However, the code for the clear button action is still present for the iPhone idiom. The issue occurs with the following steps:

1. Click a select field
2. Press the clear button
3. Click the same select field again

This is illustrated in the attached screen recording.

This could also be resolved by checking to see if self.valueID is nil at the same point we check identifier:

- (BOOL)identifierIsEqualTo:(id)identifier {
    if (!identifier || !self.valueID) return NO;

    if ([self.valueID isKindOfClass:[NSString class]]) {
        return [self.valueID isEqualToString:identifier];
    } else if ([self.valueID isKindOfClass:[NSNumber class]]) {
        return [self.valueID isEqualToNumber:identifier];
    } else if ([self.valueID isKindOfClass:[NSDate class]]) {
        return [self.valueID isEqualToDate:identifier];
    } else {
        abort();
    }

    return NO;
}

@jeffleeismyhero the nil check makes more sense here, although I'm not sure why is nil now.

I've switched this to check self.valueID for nil.

It's interesting that it's nil since the clear button sets it to @NO. I'll look into it a bit more tomorrow.

Gonna merge this since it fixes a crash, we'll look more into it in a different PR.