Pbiviz start error "LESS style/visual.less"

Question

I am following the tutorial found on https://github.com/xiaodongliang/forgeviewer_embed_in_powerbi_report to create a custom visual in PowerBi. In order to visualize the 3d model The author recommends installing the visual tools at 2.5.0 version, otherwise it won't work

npm i -g powerbi-visuals-tools@2.5.0

(I actually tried the same procedure installing the 3.2.0 instead of 2.5.0 and in fact it didn't work, the custom visual remained blank instead of showing me the model, so i'm restarting the procedure with the 2.5.0 api version)

Running the command "pbiviz start" it gives me this error:

PS C:\Users\Gian Marco Manfredi\circlecard> pbiviz start
 info   Building visual...
 error  LESS  style/visual.less :  The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined

the visual.less is

p {
    font-size: 20px;
    font-weight: bold;
    em {
        background: yellow;
        padding: 5px;
        
    }
}

and the pbiviz.json is

{
  "visual": {
    "name": "circleCard",
    "displayName": "CircleCard",
    "guid": "circleCardA2677EDA579643169880D5D3DF0E2A32",
    "visualClassName": "Visual",
    "version": "1.0.0",
    "description": "",
    "supportUrl": "",
    "gitHubUrl": ""
  },
  "apiVersion": "2.5.0",
  "author": {
    "name": "",
    "email": ""
  },
  "assets": {
    "icon": "assets/icon.png"
  },
  "externalJS": [
    "node_modules/powerbi-visuals-utils-dataviewutils/lib/index.js"
  ],
  "style": "style/visual.less",
  "capabilities": "capabilities.json",
  "dependencies": "dependencies.json",
  "stringResources": []
}

I hope somebody could help me

Thank you!