MS Teams showing welcome screen only

[Mudo121Bbc]

Describe the bug
MS Teams does not show up correctly and just shows a welcome page, as seen in the following image (the text is in german though, sry for that)

To Reproduce
Starting the MS Teams App for the local env.

Expected behavior
I would expect a logged-in User and a pop-up which shows my app and to be able to add it to a channel. I started to experience that behavior since yesterday.

VS Code Extension Information (please complete the following information):

• OS: Windows 11
• Version 5.14.1

Additional context

Logs from the Browser:

I can not understand why this happens because I did not apply any changes. The Terminal and Output Tab in VS Code shows no errors. Only the Debug Console shows a lot of errors about not being able to load source maps. Thanks in advance.

[m365-agent-toolkit-assistant]

👋 Hi @Mudo121Bbc,

Thank you for reporting this issue! We want to let you know that:

⏱️ Our team will personally review your issue
🎯 You can expect a response within 2 business days

✨ This is an AI-generated initial response
🤖 AI-Generated Preliminary Analysis:

It seems like your issue with the Microsoft Teams app showing only the welcome screen is a known problem. Here are some similar issues and their corresponding solutions:

Suggested Workaround:

1. Manual Opening of Launch URL:
   Instead of repeatedly stopping and rerunning debugging, manually open the launch URL found in the Teams Toolkit output channel in your browser.
   • You can find this URL in VS Code's output tab, copy it, and paste it directly into your browser.

Potential Causes & Solutions:

1. Cache Issue:
   Sometimes, cache issues might cause the Teams app not to load correctly. Clear your browser cache or try opening the app in an incognito window.

2. Local Environment Configuration:
   Ensure that your local environment is correctly configured. Verify the following details:

   • Correct values in launch.json and manifest.json.
   • Your local server is running and accessible.

Related GitHub Issue:

• GitHub Issue #8150 suggests this is a known issue with the Teams web client and provides similar advice.

If issues persist, please provide:

1. Development environment (e.g., VS Code/Visual Studio/CLI).
2. Teams Toolkit version.
3. Detailed reproduction steps.
4. Full error logs from Debug Console and Screenshots.

Would you like more detailed instructions on any of the steps above?

✨We'd love your feedback! Please take a moment to fill out our survey.

---

Note: This is an automated first response generated by AI. A human team member will review your issue and provide a more detailed response soon. We appreciate your patience!

[sayali-MSFT]

Hello @Mudo121Bbc ,Thank you for your inquiry about your Teams app development issue! To assist you better, could you please provide the following details?

1. Reproduction Steps: Please share the steps you took to encounter the issue.
2. Documentation Links: Any specific documentation you followed that relates to your problem.
3. Teams Client Version: What version of the Teams client are you using?
4. Code Snippets: Relevant code snippets that illustrate the issue.
5. Manifest Package: If applicable, please share the manifest package for your app.

This information will help us better understand the situation and provide a more accurate response.

[Mudo121Bbc]

1. Reproduction Steps: I simply start my MS Teams App with the VS Code Extensions. This would be the relevant launch.json. I'll always start it with "Debug (Chrome)"

    {
      "name": "Attach to Frontend (Chrome)",
      "type": "chrome",
      "request": "launch",
      "url": "https://teams.microsoft.com/l/app/${{local:TEAMS_APP_ID}}?installAppPackage=true&webjoin=true&${account-hint}",
      "presentation": {
        "group": "all",
        "hidden": true
      }
    }
  ],
  "compounds": [
    {
      "name": "Debug (Chrome)",
      "configurations": ["Attach to Frontend (Chrome)"],
      "preLaunchTask": "Pre Debug Check & Start All",
      "presentation": {
        "group": "all",
        "order": 2
      },
      "stopAll": true
    }

2. Documentation Links: There I did not follow any specific documentation. We have our MS Teams App deployed already for around two years and I just follow our process how we did it as usual.

3. Teams Client Version: Because MS Teams opens up in the Web App and with this weird welcome screen I can not get any infos about the MS Teams Version. However locally on my laptop the Version 25060.205.3499.6849 is installed. But I want to emphasize it does not start the locally MS Teams, it always opens up in a Web Browser.

4. Code Snippets: I'm not sure what makes sense to show here. If I'm not mistaken I'm not even reaching a step where my custom code is able to been shown, because I can not even add it to a team and test it. Maybe an important info is that we are developing a Teams tab app.

5. Manifest Package: I have attached the manifest file. If needed, I could even add the whole appPackage. manifest.local.json

[nliu-ms]

Hey @Mudo121Bbc , can you see logged in user in Teams client?

[Mudo121Bbc]

No I can't 🙁

We have a test Tenant with multiple Accounts to test out Teams App. However with every User I get the same screen (as posted on my initial comment), where I so no logged in user and just this welcome screen. Even with the Tenant Admin I get this screen.

I wonder if there might be some options which I could check on the Tenant.

[nliu-ms]

It's more like a Teams client issue. @Wajeed-msft can you help with it? Thanks!

[andrewconnell]

Seeing the same issue with the web client in both Chrome & Edge (both latest versions) on macOS v15.3.2, as are multiple students in a class I'm teaching.

Manually launching incognito browsers and manually pasting the URL the TTK is trying to open seems to work...

[nliu-ms]

Yes, I can reproduce it with my test tenant. Trying to route the issue to the right team.

[Mudo121Bbc]

Seeing the same issue with the web client in both Chrome & Edge (both latest versions) on macOS v15.3.2, as are multiple students in a class I'm teaching.

Manually launching incognito browsers and manually pasting the URL the TTK is trying to open seems to work...

Using an incognito browser did not help for us, I'm still getting the same Problem when using Firefox, Chrome or Edge on Windows.