Solder paste has an expiration date, so it’s likely that paste has gone after a year of storage.
You’re supposed to put it in the fringe. Personally I have had good results with the cheap dealextreme paste using my hot air station. I do not store the paste in the fridge and the first jar I bought has lasted a few months now and it still works. I have kids, and I’m not going to put the paste in the fridge. I figure it’s cheap enough that I can just reorder every few months. I also ordered syringes and syringe tips from there, but syringes ship really slowly.