In ezooimport.php, line 487 (rel. 403), the oop import routine calls

                $class = eZContentClass::fetchByIdentifier( $importClassIdentifier );
                ...
                $object = $class->instantiate( $creatorID, $sectionID );

Unfortunately

• it does not check if the call to fetchbyidentifer succeeds
• if that call returns null, we have a php fatal error on the 2nd line above
• by simple export and import of an object of 'article' class, created with plain site, the $importClassIdentifier var will be set to documentation_page
• the 'documentation_page' content class is not available in plain_site installs

Proposed fixes:

• add a check for the above php code
• alter odf.ini in the base extension, removing the line
  RegisteredClassArray[]=documentation_page