OK let's go through a checklist:
- Firstly, please make sure you do a machine reset before loading the game.
- Secondly, make sure you are running the latest distro from https://www.specnext.com/latestdistro/ and not the one that comes with the stock Next.
- Thirdly, if this still happens, can you list line 40 and let me know the first command. There is no reason is should report Nonsense in BASIC
- Finally, is your Next running anything to mod it, like an alternate boot screen or something like that?
(The driver not installed error is expected, you need to reset/reload and not RUN the program)