Compiling angular project with "An unhandled exception occurred: NGCC failed"

Reinstall the flex-layout by the command

npm i @angular/[email protected]

Switch back to FlexLayout 9.0.0-beta.31. According to its changelog, the version you're using "(...) adds support for Angular v10 and Angular CDK v10."

@angular's ModuleWithProviders isn't a generics in @angular 9.x.x. but it is in @angular 10 rc.x. FlexLayout x.x.x-beta.32 started using the generic version (ModuleWithProviders<T>), so it doesn't work anymore with @angular versions < 10. You'll need to switch back to FlexLayout 9.0.0-beta.31.

In your package.json, replace the "@angular/flex-layout": "^10.0.0-beta.32" for "@angular/flex-layout": "~9.0.0-beta.31" and run npm install again (or simply npm install @angular/[email protected]")