iOS Error: cannot init a class object

iOS Error: cannot init a class object

I am running some CloudCode (via Parse.com) in my iOS app. I am running
that code in objective-C with this snippet right here:
[PFCloud callFunctionInBackground:@"email"
withParameters:@{@"email" : @"chumbleya@gmail.com",
@"code" : @"TESTCODE"}
block:^(NSString *result, NSError *error) {
if (!error) {
NSLog(@"%@", result);
}
else {
NSLog(@"%@", result);
}
}];
However, I get this error when I run it:
*** Terminating app due to uncaught exception
'NSInvalidArgumentException', reason: '*** +[NSMutableArray<0x3b6b4c00>
init]: cannot init a class object.'
If anyone has had similar experience, let me know! Thanks