Consider the following scenario:
You install a Web Services on Devices (WSD) scanner on a computer that is running Windows 8.1 or Windows Server 2012 R2.
You try to scan images from the WSD scanner by using the modern Scan application.
You set File type to TIFF, and then you run multiple image scans. For example, you run eight scans.
In this scenario, some scanned images are in PDF format instead of TIFF format.
To resolve this issue, install update 2919355. For more information about how to obtain update 2919355, click the following article number to view the article in the Microsoft Knowledge Base:
2919355 Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 Update April, 2014
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates