Cannot access a property or method of a null object reference for simple DateFormatter.parseDateString(date);

[Ramazan Ergüder Bekrek]

Greetings to y'all

I have a simple code which us calling DateFormatter for conversion from String 
to Date like follow:

public static function parseBlobDate(date:String):Date{
                        return DateFormatter.parseDateString(date);
                }

which triggers an error : TypeError: Error #1009: Cannot access a property or 
method of a null object reference.
        at mx.formatters::DateBase$/get 
http://www.adobe.com/2006/flex/mx/internal::defaultStringKey()[D:\flex_sdk\Sources\flex-sdk\frameworks\projects\framework\src\mx\formatters\DateBase.as:195]
        at 
mx.formatters::DateFormatter$/parseDateString()[D:\flex_sdk\Sources\flex-sdk\frameworks\projects\framework\src\mx\formatters\DateFormatter.as:218]

In the function defaultStringKey when I debug to see where the error comes from 
I noticed that monthNamesLong is null which is unusual.


mx_internal static function get defaultStringKey():Array /* of String */
    {
        initialize();

        return monthNamesLong.concat(timeOfDay);
    }

this code was working before but somehow it is not anymore. What am I doing 
wrong?