> You said the writing into .odb is buggy. Do you mean it’s buggy in general or only in this specific case?
> We save the ODB most of the time in the .odb format. 

I recommend JSON. Main advantage is you can read it using JSON decoder available for any language, no need to write custom code.

Other than that, the main issue is encoding of strings. For ODB this is key names and string values.

JSON was the first to standardize escape characters what can encode all valid UTF-8 UNICODE strings,
the system of escape characters is clean, easy to understand and easy to implement. https://www.json.org/json-en.html

XML is not as well defined as JSON, i.e. go and try to find the XML BNF grammar. I am not sure if the MIDAS XML encoder
and decoder is fully UTF-8 clean, and if some unlucky combinations of characters break string encoding or decoding. This
is usually tested using a fuzzer (generates all possible, unlucky and unlikely string values). Most suspicious
would be quotes, and square and angle brackets. If some character combinations break encoding or decoding, likely
this cannot be fixed in MIDAS without breaking backwards self-compatibility (will not read old ODB files correctly).

Same applies for the ODB format, except that it is even more ad-hoc. Again, any problems are hard to fix without
breaking backward self-compatibility.

In addition, in the past, the ODB and XML decoders had trouble with very long strings, this has been
fixed some time ago.

K.O.