System does not have a finite number of solutions. Why?

The error message is ridiculous, considering that:

also does not have a finite amount of solutions. As it is, Prime will give:

and you can have:

I'd say, report it as a bug. Especially considering that Mathcad 11 gives:

Success!
Luc

Well, not every innovation is an improvement! This is especially true for Prime.
Here are the results of Prime 6 with the old muPad engine still available there, compared to your disappointing results with the new FriCas/Axiom symbol kernel.

Of course the "solution" a=any number b=c=0 is wrong, as a,b and c can't be chosen to be zero (same for x2)!

As Luc said - if you feel like doing so and think it may help, you may consider reporting your results to PTC support as a bug in the new symbolic engine.