Laravel 4 - unserialize(): Error at offset 0 of 32 bytes

Refer to this issue: laravel/framework#1526

A change in the encryption mechanism is the cause. My solution was to empty out the sessions and views that were cached in the storage folder, then run php artisan key:generate and relaunch the server. I'm not sure which part of the process fixed the issue, but I haven't seen it since.