Variable is not a CFString at this time - Error

I have got this error during the debugging through device. In simulator it is working fine. How to solve that issue?

Code:

- (IBAction)buttonDigitPressed1: (UIButton *)button
{
    NSString *integerPart = [SDKRegistry returnNSStringFromComponent:@"integerPart"];

    NSLog(@"class is %@",[integerPart class]);
    NSLog(@"pointer is %p", integerPart);

    if (!integerPart) integerPart = @"";
    NSString *one = @"1";
        integerPart = [SDKRegistry updateRegistryComponent:@"integerPart" withString:
                       [integerPart stringByAppendingString: one]];
    [self performConversion];
}

class is __NSCFConstantString pointer is 0x5922c

When I am pressing number "1", appears that error - integerPart - "Variable is not a CFString at this time"

I have tried to made the following in .m file:

Code:

NSString *integerPart; @property (nonatomic, retain) NSString *integerPart;

then in .h file:

Code:

@synthesize integerPart;

and change the code above:

Code:

integerPart = [[NSString alloc] initWithString:[SDKRegistry returnNSStringFromComponent:@"integerPart"]];
...
[integerPart release];

But nothing was changed. Please help me to find an answer to solve this.

 

Code:

@interface SDKRegistry : NSObject
{
}
+ (NSString *)returnNSStringFromComponent: (NSString *)component;


@implementation SDKRegistry : NSObject

+ (NSString *)returnNSStringFromComponent: (NSString *)component
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];    
    return [defaults stringForKey:component];
}

 

Code:

+ (NSString *)updateRegistryComponent: (NSString *)component withString: (NSString *)value
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
        
    [defaults setValue:value forKey:component];
    [defaults synchronize];
    
    return value;
}

performConversion - only update the screen.

But error appears before it on the line:

Code:

if (!integerPart) integerPart = @"";  // "Variable is not a CFString at this time"

 

class is __NSCFConstantString

pointer is 0x5922c