Is ccuserdefaults thread safe?

I’ve released an app update where I thread off some ccuserdefaults reading and writing. It has been working fine during my testing however I’m gettin numerous emails from people that after getting my update their settings are getting wiped again and again. Can threads be causing this? Any way to get their settings back and any idea what’s causing this?

No, it is not thread safe.

Apple says that NSUserDefaults is thread-safe in their documentation, isn’t CCUserDefaults just a wrapper for that? Why is it not thread safe and what are some side effects of threading read/write to it?