Null Pointer Error loading ADB File

I believe the NullPointer you see is thrown because the path used to try to load the ADB file does not match the information given in the configuration file. If you specify a fully qualified path, or make your ADB folder a part of the classpath, you are able to load it, which indicates that the problem lies with path resolution. 

The configuration file needs to contain a relative path that correctly identifies the location of the ADB given the current working directory/server base of the process that tries to load the ADB. 

Try to figure out what directory is used as a basis for file lookups in your process, and calculate the correct relative path from there. 

HTH, 

Jostein