The Expression Filter module experienced an initialization failure and could not be loaded.
This can be caused by:
Regular expression is invalid and could not be parsed.
Wildcard expression is invalid and could not be parsed.
The value expression used on a day time criteria is not specified as being of date time type.
Some configuration value is invalid. The associated event description contains the specific value that was rejected.
Identify and correct the configuration causing a problem by examining the associated event description. The following link will display all events indicating a possible problem with the Expression Filter module:
View Expression Filter Events