zendframework/zf2 — comment on commit da6b777a3568f672e8a8458b853c87cabfaa1701
File: library/Zend/Cache/Storage/Adapter/Filesystem.php line 1826
By SocalNick:

This won't work with the object cache pattern. All the callbackCache patterns try to store an array in cache. Try the follwing: https://gist.github.com/aca19f8636519976a52e