What's a hypostatic differentiation?

Have you read the change log for version 2.0.0 and up? It's here.

Basically 1.10.1d had a lot of issues where it was possible for a script to crash the application, or worse, exploit dangling pointers to hack the system.

With 2.0.0 I completely restructured the internals of the library to make it secure. With this I removed support for direct pointers in the script language, but introduced object handles instead. An object handle is basically a pointer but is reference counted so that it is guaranteed to always be valid.

So basically 2.0.0 was a redesign of the script language (which warranted the new major version), after that it's only incremental improvements like before.

I recommend that you don't use 1.10.1d for new projects. And if you are using it already then you'll have to decide if you can live with the issues (listed at the library download page), or if it is better to upgrade to the newer version.

Regards,
Andreas