cannot be run on any modern day computer or computer simulator, as it was developed during the days when LISP and PLANNER were still in development stage, and thus uses non-standard macros and software libraries which do not exist anymore

There are changes in the environment not related to the program's designer, but its users. Initially, a user could bring the system into working order, and have it working flawlessly for a certain amount of time. But, when the system stops working correctly, or the users want to access the configuration controls, they cannot repeat that initial step because of the different context and the unavailable information (password lost, missing instructions, or simply a hard-to-manage user interface that was first configured by trial and error).

"the quality in a technical system that prevents a user from restoring the system, once it has failed

Or perhaps there was no printed manual, only a link to a web page - that has since disappeared (because the provider went bust, or just changed their web content management system).

A product’s onceability is, to a certain extent, linked to its usefulness. If it is really useful, we will certainly go to considerable lengths to repair it.

Onceability can be the result of the exaggerated demand for un-memorable passwords.

I have proposed a new word for this quality: onceability.

It could be defined, tentatively, as "the quality in a technical system that prevents a user from restoring the system, once it has failed".

This, I suggest, is an inherent quality in much new technology: the fact that you, as a user, manage to do something once - but not a second time.