example spa: relative modules were not found about cookbook HOT 8 CLOSED

$ npm start

> [email protected] start /home/dmoebius/src/vue-crud-x/example-spa
> concurrently "npm run rest" "npm run serve"

[0] 
[0] > [email protected] rest /home/dmoebius/src/vue-crud-x/example-spa
[0] > cd ../backend&&npm run-script dev
[0] 
[1] 
[1] > [email protected] serve /home/dmoebius/src/vue-crud-x/example-spa
[1] > vue-cli-service serve --port 8080
[1] 
[0] 
[0] > functions@ dev /home/dmoebius/src/vue-crud-x/backend
[0] > set NODE_ENV=development&&nodemon index.js
[0] 
[1]  INFO  Starting development server...
[0] [nodemon] 1.19.1
[0] [nodemon] to restart at any time, enter `rs`
[0] [nodemon] watching: *.*
[0] [nodemon] starting `node index.js`
[0] Environment:  undefined
[0] HTTPS:  No
[0] env development
[0] KEYV_CACHE undefined
[0] use map
[0] internal/modules/cjs/loader.js:583
[0]     throw err;
[0]     ^
[0] 
[0] Error: Cannot find module '../models/User'
[0]     at Function.Module._resolveFilename (internal/modules/cjs/loader.js:581:15)
[0]     at Function.Module._load (internal/modules/cjs/loader.js:507:25)
[0]     at Module.require (internal/modules/cjs/loader.js:637:17)
[0]     at require (internal/modules/cjs/helpers.js:22:18)
[0]     at Object.<anonymous> (/home/dmoebius/src/vue-crud-x/backend/services/index.js:9:14)
[0]     at Module._compile (internal/modules/cjs/loader.js:689:30)
[0]     at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
[0]     at Module.load (internal/modules/cjs/loader.js:599:32)
[0]     at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
[0]     at Function.Module._load (internal/modules/cjs/loader.js:530:3)
[0]     at Module.require (internal/modules/cjs/loader.js:637:17)
[0]     at require (internal/modules/cjs/helpers.js:22:18)
[0]     at Object.<anonymous> (/home/dmoebius/src/vue-crud-x/backend/middleware/auth.js:1:100)
[0]     at Module._compile (internal/modules/cjs/loader.js:689:30)
[0]     at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
[0]     at Module.load (internal/modules/cjs/loader.js:599:32)
[0] [nodemon] app crashed - waiting for file changes before starting...
[1] <s> [webpack.Progress] 0% compiling
[1] <s> [webpack.Progress] 10% building 0/0 modules 0 active 
...