Excessive moisture in your chocolate will definitely thicken it. I would try pulling the nuts out of the freezer the day before or something and letting them sit out, but still sealed. Once they've warmed to room temperature, you can open them without concern of condensation.
Another option if you are working with unroasted macamdamia nuts would be to crush them in halves (or even smaller nibs) and run them through a dehydrator for 24-48 hours, to ensure moisture content is less than 1%. The equipment for this is cheap enough and you cna do a large batch at once.
A good test to make sure the moisture is gone is to ... bite into them, they should be crunchy, not soft.
If you get to that stage, you can process the nuts into a butter and keep it in a tightly sealed container for months, at room temperature outside the freezer.
Hi, Thank you both for your answers. I won't use the roasted macadamia paste into chocolate because it's very susceptible to moisture changes, I will use them for white chocolate-macadamia spread, by the past experience is amazing, I will but the paste in the oven on low heat or either roasted for less than a minute on a pan. I had just 400-500 grams of paste, not so bad.
But hey, I learned an important lesson: you don't fill change in the viscosity until you reach close to working temperature then it just become immobile.. After trying to retemper again and again you I can disapprove the possibility of over-tempering.
First time dealing with moisture - hope it want happen again, and if so I will can analyse it quickly. dehydrator is a good option, but for the future:)