SecItemCopy and SecItemAdd errors about lockbox HOT 1 OPEN

I doubt the accessibility setting has any bearing on the behavior you're seeing, but I could be wrong.

You note that you have to encode and decode your array elements. Have a look at issue #44 which has a lengthy discussion about the problems with saving nested complex objects like an array of non-standard objects. This isn't what is causing your issue, I bet, but I wanted to point it out.

Although not ideal, you might try removing the item first by setting the value to nil before setting a new value. For example:

[Lockbox setArray:nil forKey:key];
[Lockbox setArray:self.stringArray forKey:key];

In fact, just the setArray call will replace an existing value by deleting the old one then adding the new one, so this breaks up that operation a bit by explicitly removing the old value then adding the new value, which might alleviate the problem. Kind of a guess, but worth a try.

from lockbox.