windows grayed out on saving

When I hit the save button the big window (with the preview of the scanned pages) greyed out while the saving page x of all windows is displayed normally. I'm not sure if this is supposed to happen.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: simple-scan 3.20.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-17.33-generic 4.4.6
Uname: Linux 4.4.0-17-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.1-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Apr 6 22:35:46 2016
InstallationDate: Installed on 2016-03-26 (10 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160323)
MachineType: Apple Inc. MacBook4,1
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-17-generic.efi.signed root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
SourcePackage: simple-scan
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/09/08
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MB41.88Z.00C1.B00.0802091535
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Mac-F22788A9
dmi.board.vendor: Apple Inc.
dmi.board.version: PVT
dmi.chassis.asset.tag: Asset Tag#
dmi.chassis.type: 2
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F22788A9
dmi.modalias: dmi:bvnAppleInc.:bvrMB41.88Z.00C1.B00.0802091535:bd02/09/08:svnAppleInc.:pnMacBook4,1:pvr1.0:rvnAppleInc.:rnMac-F22788A9:rvrPVT:cvnAppleInc.:ct2:cvrMac-F22788A9:
dmi.product.name: MacBook4,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.