Failed to load extension from: /usr/share/chromium/extensions/icpgdjoejngfekheifhhaceealdnipfb.json. Manifest file is missing or unreadable

[LudovicRousseau]

After I fixed the GNU/Linux build I had to modify the install.sh script to install for chromium and not chrome.

I use:

    TARGET_DIR="$HOME/.config/chromium/NativeMessagingHosts"
    EXTENSION_DIR="/usr/share/chromium/extensions/"

But when I start chromium I get the error:
Failed to load extension from: /usr/share/chromium/extensions/icpgdjoejngfekheifhhaceealdnipfb.json. Manifest file is missing or unreadable

The file /usr/share/chromium/extensions/icpgdjoejngfekheifhhaceealdnipfb.json contains:

$ cat /usr/share/chromium/extensions/icpgdjoejngfekheifhhaceealdnipfb.json
{
  "external_update_url": "https://clients2.google.com/service/update2/crx"
}

The extension is installed in ~/.config/chromium/NativeMessagingHosts/org.cardid.webcard.native.json and contains:

{
  "name": "org.cardid.webcard.native",
  "description": "WebCard Native Helper Application",
  "path": "/home/rousseau/Documents/github/webcard/native/bin/webcard",
  "type": "stdio",
  "allowed_origins": [
    "chrome-extension://icpgdjoejngfekheifhhaceealdnipfb/"
  ]
}

I don't know where the Manifest file should be not what it should contain.