If you try to create a document, from an uploaded document template in SharePoint, from a "SharePoint" tab or "Website" tab in a Teams' channel, you get this error message:
"You'll need a new app to open this about link", see screenshot below:
Clicking on the "Look for an app in the Microsoft Store" link will give you no options.
Steps to reproduce the issue:
Create a document library in a SharePoint site
Open the document library and click on the "+ New" function
Select the option in the bottom of the choices "+ Add template"
Upload a new Word template (does not matter if the document is a docx file or a dotx file)
Copy the URL of the document library
Go to a channel in Teams (from the Teams Desktop Client" and add a tab, select either a "SharePoint" tab or a "Website" tab.
Paste the URL of the document library
In the newly created tab, click on the "+New" function.
Select one of the new templates that you have uploaded
You will get the error message (interesting is that you do not get the error message if you do the same thing from Teams in a web browser)
Does anyone know what I can do to avoid getting this error message?
The "Document library" tab is not an option, as it does not show any custom document templates and the standard "Files" tab is also not an option as you do not have any option to set metadata on documents. Linking document templates to a content type is also not an option, as we want to give the users the option to easily create documents from multiple document templates and thereby do not want to make things more difficult by having to create content types for these templates.