I am in the middle of a large project that outputs a heirarchical data structure to a binary file.

Sometimes when I rebuild part of the project, the older data files from a previous build won't load any more.

What is the standard procedure for making data file future proof as much as possible? I will be making many alterations to my data structure in the coming weeks and I don't want to re-enter all the data over and over again.

What to do? Hmmm.