NSData *pdfURL = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@",_paperURL]]];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDirectory = [paths objectAtIndex:0];
//line with error
NSString *file = [documentDirectory stringByAppendingFormat:[NSString stringWithFormat:@"/%@.pdf", _idNo]];
//ive also tried adding nil at the end
NSString *file = [documentDirectory stringByAppendingFormat:[NSString stringWithFormat:@"/%@.pdf", _idNo, nil]];
some answers that I've tried and didn't help are listed below. any help would be appreciated
Warning : Format string is not a string literal (potentially insecure)