It’s not a continuity error as such, but I’m a big fan of all the technologies that by rights should have completely upended galactic civilization but then just get forgotten.

The Genesis device should be an appalling superweapon that would change the face of war.

And then those missiles from Generations that can kill an entire solar system should, too.

And the time on TNG that they stumbled on a weird transporter trick that could make it so no one would ever need to die of old age ever again.

And the Tribble blood that cures death.

And so forth.

Warp 10 and salamanders. Great examples 👌

But what about TNG 7x09, the one where we learn that warp travel damages subspace and that a warp speed limit is the solution?

Later, the Federation Council issues a new directive limiting all Federation vessels to a speed of warp five except in extreme emergencies.

Laughs in Janeway

https://en.wikipedia.org/wiki/Force_of_Nature_(Star_Trek:_The_Next_Generation)