This problem only happends in a particular case, that is, the EDICT file's generated time is advanced than your current system's local time, so NJStar needs to create new index files. EDICT file is generated in Australia, time zone GMT+10, the file's generated time is stored as local time, if you download the EDICT file on the same day when it is created, most likely the above mentioned case happens.

The solutions are:

1. Download NJStar's latest upgrade patches at here.
    
2. Open NJStar one day later, or open EDICT and save it to the current system local time.