Throw an error if deprecated configurations are provided or duplicated sections exist in the config file
If the structure of the config file changes this is a high risk for errors, especially with default values and change of named sections in the json file. If a section with an deprecated name is given in the config file, throw an error and stop the program. This ensures that deprecated changes will really be removed in production as well.
E.g.
lagrangeInterpolator
changed to interpolator
and the default values have been unstable in the simulation. This was a really hard to trace bug.