i am in the process of making an app using app designer. everything was fine. i quit matlab. next day, app designer will not open it, and there is no prj file in the directory. the app itself works fine when double clicked. But as it's not finished and i need to keep editing it, I need to be able edit it. at the very least, i need to get inside and see the code so that if I have to start over it doesn't have to be totally from scratch. i originally created it in 2017b. I have since updates to 2018a, but no help. the only difference it the error message when it won't open.