The field 'world_region' has no associated option list.

[magnolia61]

Hello,
I don know where to post this exactly because I have no clue what causes this problem but let me try to describe it:

In our drupal 7.34 / civicrm 4.5.5. installation I get all kind of messages complaining about the world_region table

Error Reports show the following messages at the same moment:
1) [message] => The field 'world_region' has no associated option list.
    [exception] => CiviCRM_API3_Exception Object
2) SQLSTATE[HY000]: General error: 2006 MySQL server has gone away

The strange thing is that the world_region table in the database seems to be in good shape.
Probably it's all very easy and understandable. But right now I have no clue in which haystack I need to start looking for the needle :-)

Has anyone a clue for me where to start looking for a solution?

[Coleman Watts]

What extensions do you have installed? payment processors?
are you using geocoding?