Objective-C : Use after free

The application is trying to use the freed memory. This may lead to incorrect behavior of the application.

The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common causes:

• Error conditions and other exceptional circumstances.
• Confusion over which part of the program is responsible for freeing the memory.