IMPORTANT NOTE: The CHD format has undergone a change with this
release. The main reason for this change is to include some of the
key metadata into the hashes for the CHDs. This ensures that the
metadata is valid and prevents abuse.
The first impact you will find is that all of your CHD differencing
files are invalid. Just delete your "diff" directory contents
entirely.
The second impact is that all your existing CHDs will warn you that
they have incorrect hashes. This is expected. Your old CHDs should
still work fine, so if you can live with the "bad ROM" warnings, you
don´t really need to do anything. However, if this bugs you or you
want to be "clean", you can update your CHDs, using this command
line: