If you only change parameters, you are not supposed to repeatedly call Dynare. Rather, run Dynare only once and then use the commands you want to run in a loop directly. See [Loop over parameters)
Whenever you run dynare itself, you are running the preprocessor, which re-creates all files. It seems that your machine is not quick enough in writing these files so that the previous iteration was not done yet with writing the created files, leading to the crash.
Let me reiterate my point. Although e.g. Wouter Den Haan and Eric Sims say so in their Dynare notes, you should always avoid running full Dynare within a loop or optimizer. If anyhow possible, make use of the Dynare rountines without running the preprocessor over and over again. This typically requires only small effort and increases speed by several magnitudes.