If you ever worked with @angular-devkit package specially if you work with Ionic framework  you might have noticed following error at least once

An unhandled exception occurred: Cannot destructure property 'bold' of 'core_1.terminal' as it is undefined.

to solve this error you can run following commands in your terminal (administrator access is recommended)

npm -g install chalk

npm -g install @angular-devkit/core

And now your problem is solved.

In some cases it might not solve your problem than you can try to remove angular from your system and reinstall it globally. (use commands below)

npm uninstall -g @angular/cli

npm cache clean --force

npm install -g @angular/cli

.