ng build --prod not working

Error:

The code is generated using ng new command, not modified.

ng build works well.

The reason is that the package file generated with ng new is not using some old version libraries that are not compatible with aot option. (aot option is implicit with --prod)

To fix this issue

npm install -g npm-check-updates

ncu -u 

npm install

Then build again

 ng build --prod -aot --base-href=/tools/angular/

Problem solved 

--

Feng