[Lynne]

Hmm, google did an interesting translation - I'm not sure I understand anything except that you are getting a white page when reading your PMs. Usually, if you look at your error_logs, the real error will be listed. You might want to try disabling your plugins to see if the error goes away:
To temporarily disable the plugin system, edit config.php and add this line right under <?php

PHP Code:

define('DISABLE_HOOKS', true);