I began getting this starting with the past 2 updates (even the in-game character screens are blank) on one of my computers, so I downloaded the game on my other system that has a dedicated graphics card; not just an on-board chipset and everything works there. Not a game breaking problem but it did dampen my enjoyment of the game until I started playing on my apparently better computer.
Troubled system specs:
Intel Pentium Dual-Core E5800 processor 3.2GHz, 2MB Cache
Microsoft Windows 7 Home Premium 64-Bit Edition
3GB of DDR3 SDRAM system memory
Integrated Graphics Media Accelerator X4500HD