ERROR Error: Uncaught (in promise): Error: Cannot activate an already activated outlet

I have read online that this in an Angular app's package.json (at I guess "dependencies") might help fix this problem...

"@angular/platform-browser": "^4.4.6",
"@angular/platform-browser-dynamic": "^4.4.6",
"@angular/platform-browser/animations": "^4.4.6",

 
 

Only you wouldn't use version 4.4.6. This should really go in an Angular 5 app and I'm not working with Angular 5 so I can't get past an error reading...

npm ERR! Invalid package name "@angular/platform-browser/animations": name can only contain URL-friendly characters