unresolved reference - javadb_driver_label

[Jim0804]

I am using version 6.8 and javadb for my Java SE application development. Everything has been OK until today when I suddenly got a "unresolved reference" of JAVADB_DRIVER_LABEL referring to my projects when the IDE started up. I checked the project properties, library and it showed Javadb_driver was there, which had been there since my project was created and working. I even had been able to create database, tables, inserting etc on javadb for some time and I did not touch anything on the project setting.

I have tried to uninstall my netbeans, and re-install again. The problem still exists.

All my projects using javadb (with library pointing to the javadb library contained in Glassfish) have the same problem.

The only thing unusual I could recall was that the IDE had once started up with two windows at the same time, and it seemed hang, so I kill the start up to quit. I left for the day then.

What went wrong ?