Custom Error message from server

[iyobo]

Is there a way to feed in error messages from the server upon a failure instead of just "Internal Server Error"?

[fzaninotto]

Error message notifications are a side effect, and as such, are handled by redux-saga in admin-on-rest. If you want to display custom notifications based on certain error messages, you need to write your own sagas. And for that, you'll need to bypass the <Admin> component and write a custom app, as described here: http://marmelab.com/admin-on-rest/CustomApp.html