SOR | Polish config parsing

[4TT1L4]

Problem:

• The config parsing on startup needs some polishing, since the error messages logged on invalid config are not really helpful.

Please make sure that the error messages printed on invalid config are user friendly and help to understand the actual problem. At the moment these messages are very technical and include internal implementation details, which should not be the case.

Solution:

• Improve the config validation on startup.