Could not find an NgModule. Use the skip-import option to skip importing in NgModule

I get the error in the subject of this post when I use the CLI to create a new component: ng g c my-component --project=my-project (No component is created)

I've seen other posts with the same error message, but none of them also include Nrwl/Nx, which I believe is somehow involved. Project started as Ng4 and was upgraded to Ng6.

Environment:

Angular CLI: 6.0.8
Node: 8.9.4
OS: win32 x64
Angular: 6.0.6
@angular-devkit/architect 0.6.8
@angular-devkit/build-angular 0.6.8
@angular-devkit/build-optimizer 0.6.8
@angular-devkit/core 0.6.8
@angular-devkit/schematics 0.6.8
@angular/cdk 6.3.1
@angular/cli 6.0.8
@angular/material 6.3.1
@ngtools/webpack 6.0.8
@schematics/angular 0.6.1
@schematics/update 0.6.8
rxjs 6.2.1
typescript 2.7.2
webpack 4.8.3
nrwl/nx 6.1.0

UPDATE #1

I tried dropping the --project flag entirely ( so just ng g c my-component) and still get the same problem. Not sure what that means, yet.

Solution

I ended up totally deleting node_modules, clearing out the yarn cache and then running yarn to reinstall all packages. I also edited my angular.json file so that my pathing looked like this for all applications and libraries:

"root": "libs/my-lib",
"sourceRoot": "libs/my-lib/src"

I'm not sure which of those fixed the problem, but all appears to be OK now. At least the immediate problem went away.