EmberJS from less to sass with bootstrap convert

I am doing step by step according to

https://bushbaby.nl/emberjs-sass-bootstrap/

but i am ending up with error

martinko5mb@debian:~/Projects/XXX$ ember install ember-bootstrap
WARNING: Node v12.18.3 is not tested against Ember CLI on your platform. We recommend that you use the most-recent "Active LTS" version of Node.js. See https://git.io/v7S5n for details.
WARNING: Ember CLI is using the global npm, but your npm version has not yet been verified to work with the current Ember CLI release.
npm: Installed ember-bootstrap
installing ember-bootstrap
Installing for Bootstrap 4 using preprocessor sass
  uninstall bower package bootstrap-sass
  install package bootstrap
WARNING: Ember CLI is using the global npm, but your npm version has not yet been verified to work with the current Ember CLI release.
npm: Installed bootstrap@^4.3.1
Added import statement to app/styles/app.scss
Added ember-bootstrap configuration to ember-cli-build.js
Installed addon package.
martinko5mb@debian:~/Projects/XXX$ ember s
WARNING: Node v12.18.3 is not tested against Ember CLI on your platform. We recommend that you use the most-recent "Active LTS" version of Node.js. See https://git.io/v7S5n for details.
Could not start watchman
Visit https://ember-cli.com/user-guide/#watchman for more info.
Template Compiler Error (broccoli-persistent-filter:TemplateCompiler) in ember-popper/templates/components/ember-popper-targeting-parent.hbs

Assertion Failed: '@id' is not a valid path. ('ember-popper/templates/components/ember-popper-targeting-parent.hbs' @ L10:C12) 


Stack Trace and Error Report: /tmp/error.dump.4d09eefb1bc452f18a3bd776af5c84b0.log

And the error.dump.4d09eefb1bc452f18a3bd776af5c84b0.log looks like:

=================================================================================
ENV Summary:

  TIME: Mon Aug 24 2020 14:36:17 GMT+0200 (Central European Summer Time)
  TITLE: ember
  ARGV:
  - /usr/bin/node
  - /usr/bin/ember
  - s
  EXEC_PATH: /usr/bin/node
  TMPDIR: /tmp
  SHELL: /bin/bash
  PATH:
  - /home/martinko5mb/.ebcli-virtual-env/executables
  - /home/martinko5mb/.pyenv/versions/3.7.2/bin
  - /home/martinko5mb/.rvm/gems/ruby-2.7.0/bin
  - /home/martinko5mb/.rvm/gems/ruby-2.7.0@global/bin
  - /home/martinko5mb/.rvm/rubies/ruby-2.7.0/bin
  - /usr/local/bin
  - /usr/bin
  - /bin
  - /usr/local/games
  - /usr/games
  - /home/martinko5mb/.rvm/bin
  - /home/martinko5mb/.rvm/bin
  - /home/martinko5mb/.rvm/bin
  PLATFORM: linux x64
  FREEMEM: 170614784
  TOTALMEM: 16747925504
  UPTIME: 24726
  LOADAVG: 1.99853515625,1.36474609375,1.068359375
  CPUS:
  - AMD Ryzen 5 2600 Six-Core Processor - 1686
  - AMD Ryzen 5 2600 Six-Core Processor - 2341
  - AMD Ryzen 5 2600 Six-Core Processor - 3788
  - AMD Ryzen 5 2600 Six-Core Processor - 3432
  - AMD Ryzen 5 2600 Six-Core Processor - 3782
  - AMD Ryzen 5 2600 Six-Core Processor - 3045
  - AMD Ryzen 5 2600 Six-Core Processor - 1839
  - AMD Ryzen 5 2600 Six-Core Processor - 2269
  - AMD Ryzen 5 2600 Six-Core Processor - 3784
  - AMD Ryzen 5 2600 Six-Core Processor - 3124
  - AMD Ryzen 5 2600 Six-Core Processor - 3782
  - AMD Ryzen 5 2600 Six-Core Processor - 3777
  ENDIANNESS: LE
  VERSIONS:
  - ares: 1.16.0
  - brotli: 1.0.7
  - cldr: 37.0
  - http_parser: 2.9.3
  - icu: 67.1
  - llhttp: 2.0.4
  - modules: 72
  - napi: 6
  - nghttp2: 1.41.0
  - node: 12.18.3
  - openssl: 1.1.1g
  - tz: 2019c
  - unicode: 13.0
  - uv: 1.38.0
  - v8: 7.8.279.23-node.39
  - zlib: 1.2.11

ERROR Summary:

  - broccoliBuilderErrorStack: Error: Assertion Failed: '@id' is not a valid path. ('ember-popper/templates/components/ember-popper-targeting-parent.hbs' @ L10:C12) 
    at new EmberError (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:6939:25)
    at /home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:7187:13
    at PathExpression (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:15381:54)
    at visitNode (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3197:39)
    at visitKey (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3237:23)
    at visitNode (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3212:17)
    at visitKey (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3237:23)
    at visitNode (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3212:17)
    at visitArray (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3254:22)
    at visitKey (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3235:13)
  - code: [undefined]
  - codeFrame: Assertion Failed: '@id' is not a valid path. ('ember-popper/templates/components/ember-popper-targeting-parent.hbs' @ L10:C12) 
  - errorMessage: Build Canceled: Broccoli Builder ran into an error with `broccoli-persistent-filter:TemplateCompiler` plugin. 💥
Assertion Failed: '@id' is not a valid path. ('ember-popper/templates/components/ember-popper-targeting-parent.hbs' @ L10:C12) 
  - errorType: Template Compiler Error
  - location:
    - column: [undefined]
    - file: ember-popper/templates/components/ember-popper-targeting-parent.hbs
    - line: [undefined]
    - treeDir: /home/martinko5mb/Projects/XXX/tmp/broccoli_persistent_filtertemplate_compiler-input_base_path-XzGXowua.tmp
  - message: Build Canceled: Broccoli Builder ran into an error with `broccoli-persistent-filter:TemplateCompiler` plugin. 💥
Assertion Failed: '@id' is not a valid path. ('ember-popper/templates/components/ember-popper-targeting-parent.hbs' @ L10:C12) 
  - name: Error
  - nodeAnnotation: broccoli-persistent-filter:TemplateCompiler
  - nodeName: broccoli-persistent-filter:TemplateCompiler
  - originalErrorMessage: Assertion Failed: '@id' is not a valid path. ('ember-popper/templates/components/ember-popper-targeting-parent.hbs' @ L10:C12) 
  - stack: Error: Assertion Failed: '@id' is not a valid path. ('ember-popper/templates/components/ember-popper-targeting-parent.hbs' @ L10:C12) 
    at new EmberError (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:6939:25)
    at /home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:7187:13
    at PathExpression (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:15381:54)
    at visitNode (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3197:39)
    at visitKey (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3237:23)
    at visitNode (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3212:17)
    at visitKey (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3237:23)
    at visitNode (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3212:17)
    at visitArray (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3254:22)
    at visitKey (/home/martinko5mb/Projects/XXX/node_modules/ember-source/dist/ember-template-compiler.js:3235:13)

=================================================================================

I am fairly new to the EmberJS, and trying to update the thing in existing project (currently at ember-cli 2.18 succesfuly) I use bootstrap on rails projects, which converted to sass in the past few years. That is why i am doing this.

Anyway, what am i missing ?