Long POST vars included in Authorization HTTP header cause error

Yes, the class was supporting too many OAuth servers and that was making it hard to maintain. So most OAuth servers except the most used were moved to the external configuration file. This was mentioned in the changes of a previous version.

Anyway, the Initialize function fails if the configuration file is not present. Probably you are not checking for the return value of the Initialize function. You should always check it as it may fail for some reason, which is the case of missing configuration.