Loop crashes

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.