Premise invalid, if the conclusion is fallacious?

Well, in my example you can't say that B doesn't follow logically A.
If you like a person's idea, there is a significant probability that you like that person, but it can never be 100% sure.
That's why you can't consider the A false, if the B can't be true due to other evidence.

Yes, I agree there is not enough information, but the probability that A leads to B depends also from everyone's point of view and logic.
For someone A could be crucial information, for others could have little significance.

Anyway, the point is that when the "A-->B" is not a rule (even if it happens at 99% and even if B depends at 99% from A) , and you debunk B, then you can't discard A.
That's the main point of my thread.

I think Jim Tarsi nailed the first part of your question. As for the second, there is no direct causal linkage between liking a person’s idea and liking the person, though (given human nature) this often happens. Great ideas have come from unlikable, sometimes thoroughly despicable people and terrible ideas have originated from highly likable individuals. As a recipient of an idea, concept, or policy it takes disciplined objectivity to process and assess its veracity or value, independent of its source. While we each achieve this inconsistently, this forum is a constant reminder of its importance.

The question is not A that is false if the conclusion B is false, but the logical connection between A and B. Without more information what you have here is a non-sequitur, where B does not follow logically A.

The example of the drones is a good one and it shows that even if the fallacious conclusion follows logically the premise, the premise is still true.
Thank you for your responses and that you confirmed my thoughts.
But If should you give a name to the fallacy, what would that be??
I mean the fallacy of my second example, that A (premise) must be false.
Can we say "non sequitur"??

In the wikipedia page of "non sequitur" it has some subcategories.
Affirming the consequent, Denying the antecedent, Affirming a disjunct, Denying a conjunct, Fallacy of the undistributed middle.

Affirming the consequent says:
1 - If A is true, then B is true.
2 - B is true.
3 - Therefore, A is true.

My example is similar to that, but instead of "true" in numbers 2 and 3, I put false.
1 - If A is true, then B is true.
2 - B is false (could be false by probability/logic. not necessarily by evidence).
3 - Therefore, A is false.

So, can we say the same "Affirming the consequent" for this case??

In logic, there are sound arguments, and there are valid arguments. An argument is sound if the conclusions follow from the premises, whether or not the premises are true. For example:

All sheep have three legs.
Dolly is a sheep.
Therefore, Dolly has three legs.

This is a sound argument.

A valid argument is a sound argument in which all the premises are true. To continue the above example, while it is sound, it is not valid, because the first premise is false.

The bottom line (taking the long way) is that an argument can be sound or unsound, and that is not affected by the truth of the premises. Your example 1 is an unsound argument:

B is a conclusion of A.
B is fallacious.
Therefore, A is false.

"Drones kill innocent people, so military spending needs to be curtailed" is a fallacious argument (I think it's a non sequitur ), but the premise is true.

Your example 2 is similar. The conclusion that you must be friends with the person is a generalization, therefore fallacious. However, you may very well agree with his idea.

I hope this answers the question you asked. If not, I'll be happy to try again.