I just got the Imperial Max and on first boot when trying to install or update apps I received an insufficient storage error. The phone showed I had 9GB free and all that was installed were the preinstalled apps. I tried doing a factory data reset twice but still received the same error. I couldn't even use Hangouts as it said I had to update it, which was not possible.
Eventually I solved this by going into settings, storage, and clicking the cache and clearing it. After that I was able to update and install new apps