You'll need a new app to open this osf-roaming.16 message when starting Outlook 2016
Original KB number: 4230296
When you try to start Outlook 2016, you receive a Do you want to allow this website to open an app on your computer? message.
If you select Allow, you receive a You'll need a new app to open this osf-roaming.16 message.
This issue occurs when the Click-to-Run version of Microsoft Office Professional Plus is installed on the system together with the App-V version of Microsoft Visio or Microsoft Project.
To resolve this issue, deploy the Click-to-Run or MSI version of Visio 2016 or Project 2016.
For more information about how to deploy Visio 2016 or Project 2016, see Deploying Microsoft Office 2016 by Using App-V.