When using version 3.2.0, Ioniс wants to transfer me to the latest version, in case of failure, an error appears and nothing else happens.
Hi @Rudeblory,
Open the package.json of the project and check that you have "@ionic/app-scripts": "3.2.2" as a devDependency, and run npm install.
By the way, it’s totally safe to update the Ionic CLI to version 4. It supports both Ionic 3 and Ionic 4 projects 
Best,
Rodrigo