dequeueOperations crash

[rabbitmouse]

if (!self.suspended)
{
NSInteger count = MIN([self.operations count], self.maxConcurrentRequestCount ?: INT_MAX);
for (int i = 0; i < count; i++)
{
//crash in here , cout > self.operations.count......NSRangeException
[(RQOperation *)self.operations[i] start];
}
}