Microsoft Teams tab is unable to save settings during the adding to a channel

Question

Context:

I try to write a simple Microsoft Teams tab that displays a feed list. I'm able to side load my tab to Teams and to select it from the Channel "+" menu.

Problem:

If I want to save my settings, an error text appears that says "We couldn't save your tab settings. Please try again." There is no error in my browser's javascript error console.

My config.html tab javascript code:

<script type="text/javascript">
    microsoftTeams.initialize();
    microsoftTeams.settings.registerOnSaveHandler(function (saveEvent) {

        microsoftTeams.settings.setSettings({
            entityId: "example",
            contentUrl: "https://example.com/tab.html",
            suggestedDisplayName: "example",
            websiteUrl: "https://example.com",
            removeUrl: "https://example.com/remove.html"
        });

        saveEvent.notifySuccess();
    });

    function onClick() 
    {
        microsoftTeams.settings.setValidityState(true);
    }
</script>

My manifest.json

{
  "$schema": "https://statics.teams.microsoft.com/sdk/v0.4/manifest/MicrosoftTeams.schema.json",
  "manifestVersion": "0.4",
  "id": "ee90834a-d649-458d-a4e2-0b0f8d425c11",
  "version": "1.0",
  "name": "WINSider Community Deutschland",
  "developer": {
      "name": "WINSider Community Deutschland",   
      "websiteUrl": "https://windowscommunity.de",
      "privacyUrl": "https://windowscommunity.de/de/impressum/",
      "termsOfUseUrl": "http://windowscommunity.de/de/impressum/"
  },
  "tabs" : [{
    "id": "ee90834a-d649-458d-a4e2-0b0f8d425c11",
    "name": "WINSider Community",
    "description" : {
      "short": "WINsider article list as a tab",
      "full": "Summarizes the windowscommunity.de blog posts as a clickable list."
    },
    "icons": {
      "44": "icon44.png",
      "88": "icon88.png"
    },
    "accentColor" : "#37A3CF",
    "configUrl": "https://tscholze.github.io/public/teamstab/config.html",
    "canUpdateConfig": true
  }],
  "needsIdentity": false,
  "validDomains": [
      "*.github.io",
      "*.github.com",
      "*.googleapis.com",
      "*.microsoft.com",
      "*.rss2json.com",
      "*windowscommunity.de"
  ]
}

Answer 1

For your information

David posted the answers as a comment to my Github issue. Thank you.

Long story short *example.org to allow domain calls like http://example.org and http://www.example.org is not a valid definition oaf a validDomain.

Answer 2

It looks like your contentUrl, websiteUrl, and removeUrl are using domains not in your validDomains list. This will cause the save to fail.