Ya just heat it up before you pin, I had to do the same thing every time for same sources TNE, had no problem with crystallizing in muscle or anything like that, but it would always crash when cooled. Product worked fine too no problems.

The hot plate part of the coffee marker or just a pan on the stove. Swirl every few mins till it re suspends.

Yea that is typical of npp bro it crashes frequently thats why a good source in winter will add a little eo and that helps very much but anyways little off topic you got to remember each compound has a different melting point so find out what npp's is and throw it in a boiling pan of water

When heating it up, if u have any benzoyl benzoate try adding very small amounts at a time while heating up as it should help hold it in suspension, making sure to release built up air pressure inside the vial. Take note on how much u add tho so you can adjust how much you pin. Thats another way otherwise heat it up every time you pin

put a needle in the top( to ventilate), put in oven at 350 on a baking sheet for 5 minutes.... always works for me. other way is hair drier.