"You'll Need a New App to Open this About" in SPO DocLibrary Website Tab
Add a Tab to any channel
Select the "Website" type
Enter the URL for a SharePoint Team Doc library (this is required for libraries that exceed the list item limit in teams)
Click on your new Tab
Search for thing in the search box
Click on a search result
Observe the following error asking you to find an app in the App store:
"You'll Need a New App to Open this About"
Work around: Select "See more results"
Alternative: click on the 'link' under each search result to open a new browser window.