I am running Comsol 5.5, on win 7, 64 bit, with 32 GB of RAM, Solving a simple thermal stress problem. It was fine around 2 months ago, but now when I run that very same model, the answers aren't correct, and I found out 3 things: 1) when I plot for example temperature, it has a correct outcome for the few first steps, and then the plot doesn't change anymore ( so I guess the solver didn't solve the problem for the other steps) 2) before this very model was using 20-30 GB of RAM, and now it only uses 2-3 GB. 3) I have around 4500 time steps when I reduce the time steps, the number of steps with correct answer increases.
I can't stress this enough, 2 months ago it was working fine... I even uninstalled and then installed the Comsol again, and it didn't work.