Pycharm cannot run file after winpython update

After updating from WinPython-64bit-3.5.2.3Qt5 (and deleting this) to WinPython-64bit-3.6.1.0Qt5, Pycharm was unable to run the file I was working on.  It shows a popup window that says it did not find python.exe in the directory where my files are, which is of course the wrong location.  Clearing the project and default interpreter settings and setting them again does not change anything.  Meanwhile it runs other files without any problem, and if I rename my file to a new name then it runs that also without problem. But if I rename my file to the original name the problem returns, and it does not run.  If I re-install WinPython-64bit-3.5.2.3Qt5 then it does run, but it runs in the old Python3.5 of that distribution, instead of the new Python 3.6 that the project and default interpreter settings now point to.

I can work by renaming my file, but this seems like a bug,