1. It's a run-on sentence. There should be a period, or at least semicolon, before “however”. Using a proper conjunction like “but” is possible too, but then the comma following it needs to go.

2. Putting both “also” and “too” in the second clause is redundant.

I agree with #1, but I don't think the also/too redundancy is ungrammatical. It's superfluous but syntactically valid.

That's true, but it also has a grammar error: There should be a comma "," before "too".