A problem occurred evaluating project ‘:app’. > path may not be null or empty string. path=’null’

For me it was a pathing problem.

I was following the flutter guide https://flutter.io/docs/deployment/android

Create a file named <app dir>/android/key.properties that contains a reference to your keystore:

For some reason I (wrongfully) placed my “key.properties” in the app_dir/android/app folder, and this gave me the error.

* What went wrong:
A problem occurred evaluating project ':app'.
> path may not be null or empty string. path="null"

So check your pathing, and where your files are located 🙂

Bonus info:
What helped med was checking the “gradle.build” file with different settings, and it was always the storeFile file(keystoreProperties[‘storeFile’]) that gave me problems.
Try commenting it out, or change it to:

storeFile file("key.jks")  

If this works, you know that you have the correct path to your “key.jks” file. Then try introducing the poperties file (keystoreProperties)
Like

storeFile file(keystoreProperties['storeFile']) 

This did not work at first, but it does now 🙂

So check again that you “key.jks” and “key.properties” files are located the “correct” places, and how you point to them.