Sometimes no matter how simple your pintool is when it's run against the target it crashes. Recently I investigated such crash. One of my pintool was randomly crashed/hung/terminated as well as displayed memory errors.
My target was added to EMET (Enhanced Mitigation Experience Toolkit). Also, EMET was running at the time of experiment. I was thinking... what if I stop EMET? I disabled all the mitigations in EMET and stopped its service. Re-launched my pintool and checked if EMET.dll and EMET64.dll are not loaded in the target's process. This time my pintool was running without any obstacle.
Third party programs can make a pintool to crash. Of course, it's not a surprise but it's something to be aware of when working with a pintool.
If your pintool is still crashing you may want to take look at one of my earlier post.