error updating to Yosemite. Fails before reboot to install, please try again message.

error updating to Yosemite. Fails before reboot to install, please try again message. Have tried several times, cleared and re downloaded, ran disk utility and verified disk and repaired disk permissions.

Console messages read as follows:

PUKDiskPickerHorizontalMatrix is implemented in both /System/Library/PrivateFrameworks/PackageKit.framework/Frameworks/PackageUIKit. framework/Versions/A/PackageUIKit and /Applications/Install OS X Yosemite.app/Contents/PlugIns/IA.bundle/Contents/MacOS/IA. One of the two will be used. Which one is undefined.

2015-04-21 9:58:02.510 AM launchservicesd[56]: Application App:"Install OS X Yosemite" asn:0x0-39039 pid:3724 refs=7 @ 0x7f9e1051af60 tried to be brought forward, but isn't in fPermittedFrontApps ( ( "LSApplication:0x0-0x3a03a pid=3734 "SecurityAgent"")), so denying. : LASSession.cp #1481 SetFrontApplication() q=LSSession 100006/0x186a6 queue

2015-04-21 9:58:02.510 AM WindowServer[95]: [cps/setfront] Failed setting the front application to Install OS X Yosemite, psn 0x0-0x39039, securitySessionID=0x186a6, err=-13066

2015-04-21 9:58:02.572 AM authexec[3737]: executing /Applications/Install OS X Yosemite.app/Contents/Resources/InstallAssistantTool

2015-04-21 9:59:10.000 AM kernel[0]: hfs: mounted OS X Base System on device disk2s2

2015-04-21 9:59:10.082 AM mds[38]: (Normal) Volume: volume:0x7fcb149db000 ********** Bootstrapped Creating a default store:1 SpotLoc:(null) SpotVerLoc:(null) occlude:0 /Volumes/OS X Base System

2015-04-21 9:59:13.000 AM kernel[0]: hfs: unmount initiated on OS X Base System on device disk2s2

2015-04-21 10:00:14.164 AM mds[38]: (Normal) Volume: volume:0x7fcb149c9000 ********** Bootstrapped Creating a default store:1 SpotLoc:(null) SpotVerLoc:(null) occlude:0 /Volumes/OS X Install ESD

2015-04-21 10:01:11.381 AM InstallAssistant[3724]: NSDistantObject (0x60000006cfc0) is invalid (no connection)

2015-04-21 10:01:27.255 AM Console[3766]: setPresentationOptions called with NSApplicationPresentationFullScreen when there is no visible fullscreen window; this call will be ignored.