"Add-in Error: We couldn't get the information needed to start this add-in." when adding Mentimeter add-in for PowerPoint Web

[Augustalex]

Reproduction steps:

1. Create a new presentation in PowerPoint Web.
2. Insert a new add-in, select Mentimeter from the Store tab. This will add the add-in to your first slide.
3. The add-in will try to load and show this message:
   "Add-in Error: We couldn't get the information needed to start this add-in."

Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: Office on the web
• Host [Excel, Word, PowerPoint, etc.]: Powerpoint Web
• Operating System: Mac 12.5.1
• Browser (if using Office on the web): Chrome 106.0.5249.119

Expected behavior

The app should show a green spinner and then start loading the target website (the Mentimeter app).

Current behavior

It does not send a request to the target website, it shows the error right away.

It seems to only affect PowerPoint Web and not the desktop app.

Context

I'm an Engineer at Mentimeter. We discovered this issue sometime last week.

[RuizhiSunMS]

Onur Onder (@ononder) Please take a look.

[Augustalex]

When I press "Present", the add-in successfully loads while presenting.

It seems to only show this error when editing the presentation.

Which still makes it a very big concern for our users using it with PowerPoint Web.

[Augustalex]

We are getting a lot of support tickets regarding this error from our users. Is there any news to share, or anything you suggest we look into?

From our end the issue is very much a black box - hard to find out anything at all besides from the error shown.

[gingerjia]

August Alexandersson (@Augustalex) thanks very much for reporting the issue! I can repro the issue from my side and found the failure is due to there is notHttps Domain URL in your add-in mainfest: "http://adfs.lu.se". This is not allowed and throw the error message.
Please let us if the issue isn't resolved by fixing the protocol. Thanks!

[Augustalex]

Thanks!

I'll upload an updated manifest and see if that solves it, or if there is anything else.

[Augustalex]

It's uploaded. Let's see after it goes through certification ✅

[Augustalex]

It seems to be working now 👍