"Loading project tsconfig.json" is slow or permanent in Angular project

Problem

Loading tsconfig takes a long time in Angular projects.

Cause 

The TypeScript language service does not have sufficient memory in large Angular projects.

Resolution

1. Set the TypeScript language service memory limit directly in the UI:
   • Navigate to Settings | Languages & Frameworks | TypeScript > Language Services Memory.
   • Set the memory limit to a larger value.
   • Click Apply.
   • Restart the service using the widget in the status bar or by reopening the project.
2. If it doesn't help, disable the service-powered type engine in Settings | Languages & Frameworks | TypeScript | Angular and restart the IDE.