I made a GUI in app designer 2018. Now, after updating to 2019a and trying to open my app, I received the message "undefined function 'appdesigner.internal.componentcontroller.DesignTimeController' for input argument of type 'matlab.ui.control.Label'.
I received a similar message trying to open another app created with 2018 Matlab version.
The great problem is that I cannot edit the code to try to solve the problem, because it doesn't open.
Thank you in advance,