Thanks for the reply, Linc.
I performed the prescribed actions and indeed, something has changes: Now when I go to the "Updates" page in the Appstore and click "update" e.g. for El Capitan 10.11.3, the system starts to download and continues to download, i.e. blue time bar goes all the way to its end. It does no longer just go 1-2 mm for 5 secs and stops. So far, so good. However, this does NOT help! Once download is completed in the Appstore, Restart is said to be required. After restart, the system software version still is and remains 10.11.2 !! ...no update ! I performed update attempts 2-3 times using "update all" or individual updates. Prior to my last attemp to "update all" I cleared the console and below is the listing of what happened after I tried once more to "update all"
....now what
asks
Peter
---------------------
31.01.16 17:45:02,166 WindowServer[178]: send_datagram_available_ping: pid 431 failed to act on a ping it dequeued before timing out.
31.01.16 17:45:05,601 App Store[484]: Unknown class FRToolbar in Interface Builder file at path /System/Library/PrivateFrameworks/StoreUI.framework/Resources/Base.lproj/FRStor eViewController.nib.
31.01.16 17:45:07,113 storeaccountd[351]: -[PushServiceStoreDispatch getEnabledMediaTypesWithReply:]
31.01.16 17:45:08,000 kernel[0]: Limiting closed port RST response from 262 to 250 packets per second
31.01.16 17:45:09,000 kernel[0]: hfs: mounted Recovery HD on device disk0s3
31.01.16 17:45:09,473 mds[66]: (Volume.Normal:2464) volume:0x7fd37e054800 ********** Bootstrapped Creating a default store:0 SpotLoc:(null) SpotVerLoc:(null) occlude:0 /Volumes/Recovery HD
31.01.16 17:45:09,486 mdworker[462]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,486 mdworker[466]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,487 mdworker[464]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,488 mdworker[465]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,491 mdworker[463]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,492 mdworker32[467]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,493 mdworker32[468]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,496 mdworker[478]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,497 mdworker[480]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,499 mdworker[481]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,500 mdworker[479]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,501 mdworker[471]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,501 mdworker[473]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,501 mdworker[472]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,502 mdworker[474]: (ImportBailout.Error:1325) Asked to exit for Diskarb
31.01.16 17:45:09,519 fseventsd[52]: Logging disabled completely for device:1: /Volumes/Recovery HD
31.01.16 17:45:09,000 kernel[0]: hfs: unmount initiated on Recovery HD on device disk0s3
31.01.16 17:45:09,607 sandboxd[139]: ([494]) DesktopServicesH(494) System Policy: deny file-write-mode /Volumes/Recovery HD/.Trashes/501
31.01.16 17:45:10,328 sandboxd[139]: ([431]) softwareupdated(431) deny system-fsctl 0x682f
31.01.16 17:45:10,659 sandboxd[139]: ([431]) softwareupdated(431) deny system-fsctl 0x682f
31.01.16 17:45:10,969 sandboxd[139]: ([431]) softwareupdated(431) deny system-fsctl 0x682f
31.01.16 17:45:16,893 com.apple.xpc.launchd[1]: (com.apple.FileSyncAgent.PHD.isRunning) The HideUntilCheckIn property is an architectural performance issue. Please transition away from it.
31.01.16 17:45:16,901 com.apple.xpc.launchd[1]: (com.apple.speech.speechsynthesisd) This key does not do anything: OnDemand
31.01.16 17:45:16,902 com.apple.xpc.launchd[1]: (com.apple.trustd.agent) This key does not do anything: OnDemand
31.01.16 17:45:16,903 com.apple.xpc.launchd[1]: (com.apple.trustd.agent) The ServiceIPC key is no longer respected. Please remove it.
31.01.16 17:45:16,903 com.apple.xpc.launchd[1]: (com.apple.TrustEvaluationAgent) This key does not do anything: OnDemand
31.01.16 17:45:16,918 tccd[503]: Failed to create /var/empty/Library/Application Support/com.apple.TCC (13)
31.01.16 17:45:17,105 sandboxd[139]: ([502]) AssetCacheLocato(502) deny mach-lookup com.apple.cookied
31.01.16 17:45:24,646 com.apple.xpc.launchd[1]: (com.apple.appkit.xpc.sandboxedServiceRunner) The JoinExistingSession key is only available to Application services.
31.01.16 17:45:47,706 fontd[514]: ATS is unable to switch to Read/Write database - ATS will run off of a read-only database. Only System Fonts will be available.
31.01.16 17:45:58,991 locationd[89]: Could not finalize statement, error code = 8, error message = attempt to write a readonly database:
31.01.16 17:45:58,991 locationd[89]: Could not finalize statement, error code = 8, error message = attempt to write a readonly database: �� B?
31.01.16 17:45:58,991 locationd[89]: Could not prepare statement CREATE TABLE WifiLocationCounts (Count INTEGER), error code = 1, error message = table WifiLocationCounts already exists
31.01.16 17:46:11,072 WindowServer[178]: send_datagram_available_ping: pid 431 failed to act on a ping it dequeued before timing out.
31.01.16 17:47:22,100 WindowServer[178]: send_datagram_available_ping: pid 431 failed to act on a ping it dequeued before timing out.
31.01.16 17:48:21,882 WindowServer[178]: send_datagram_available_ping: pid 431 failed to act on a ping it dequeued before timing out.
31.01.16 17:52:56,000 syslogd[49]: ASL Sender Statistics
31.01.16 17:52:58,933 locationd[89]: Could not write data to disk /var/folders/zz/zyxvpxvq6csfxvn_n00000sm00006d/C/cache.plist
31.01.16 17:53:40,000 kernel[0]: en0: Received EAPOL packet (length = 145)
31.01.16 17:53:40,000 kernel[0]: inputEAPOLFrame: 0 extra bytes present in EAPOL frame.
31.01.16 17:53:40,000 kernel[0]: inputEAPOLFrame: decrypting key data
31.01.16 17:53:40,000 kernel[0]: inputEAPOLFrame: Received message 1 of 2
31.01.16 17:53:40,000 kernel[0]: installGTK: setting cipher key (flags = 0x0)
31.01.16 17:53:40,000 kernel[0]: GTK-RSC: 00 00 00 00 00 00
31.01.16 17:53:40,000 kernel[0]: GTK: 4d 81 03 c8 be 3a 3d b4 65 07 a4 fc 25 20 b4 f5
31.01.16 17:53:40,000 kernel[0]: installGTK: GTK installed
31.01.16 17:58:21,935 WindowServer[178]: send_datagram_available_ping: pid 431 failed to act on a ping it dequeued before timing out.
31.01.16 17:58:22,485 launchservicesd[84]: Application App:"loginwindow" asn:0x0-2002 pid:100 refs=8 @ 0x7f8b32f2d5f0 tried to be brought forward, but isn't in fPermittedFrontApps ( ( "LSApplication:0x0-0x33033 pid=524 "ScreenSaverEngine"")), so denying. : LASSession.cp #1531 SetFrontApplication() q=LSSession 100007/0x186a7 queue
31.01.16 17:58:22,485 WindowServer[178]: [cps/setfront] Failed setting the front application to loginwindow, psn 0x0-0x2002, securitySessionID=0x186a7, err=-13066
31.01.16 17:58:22,491 launchservicesd[84]: Application App:"loginwindow" asn:0x0-2002 pid:100 refs=9 @ 0x7f8b32f2d5f0 tried to be brought forward, but isn't in fPermittedFrontApps ( ( "LSApplication:0x0-0x33033 pid=524 "ScreenSaverEngine"")), so denying. : LASSession.cp #1531 SetFrontApplication() q=LSSession 100007/0x186a7 queue
31.01.16 17:58:22,491 WindowServer[178]: [cps/setfront] Failed setting the front application to loginwindow, psn 0x0-0x2002, securitySessionID=0x186a7, err=-13066
31.01.16 17:58:22,705 com.apple.xpc.launchd[1]: (com.apple.xpc.launchd.domain.user.501) Service "com.apple.xpc.launchd.unmanaged.loginwindow.100" tried to hijack endpoint "com.apple.tsm.uiserver" from owner: com.apple.SystemUIServer.agent
31.01.16 17:58:22,705 com.apple.xpc.launchd[1]: (com.apple.xpc.launchd.domain.user.501) Service "com.apple.xpc.launchd.unmanaged.loginwindow.100" tried to hijack endpoint "com.apple.tsm.uiserver" from owner: com.apple.SystemUIServer.agent
31.01.16 17:58:25,150 loginwindow[100]: ERROR | -[LWBuiltInScreenLockAuthLion closeAuthAndReset:] | Attempted to remove an observer when not observing
31.01.16 17:58:25,688 Dock[271]: -[UABestAppSuggestionManager notifyBestAppChanged:type:options:bundleIdentifier:activityType:dynamicIdentifi er:when:confidence:deviceName:deviceIdentifier:deviceType:] (null) UASuggestedActionType=0 (null)/(null) opts=(null) when=2016-01-31 16:58:25 +0000 confidence=1 from=(null)/(null) (UABestAppSuggestionManager.m #319)
31.01.16 18:00:09,892 sandboxd[139]: ([431]) softwareupdated(431) deny system-fsctl 0x682f
31.01.16 18:00:17,642 WindowServer[178]: send_datagram_available_ping: pid 431 failed to act on a ping it dequeued before timing out.
31.01.16 18:00:24,874 sandboxd[139]: ([431]) softwareupdated(431) deny system-fsctl 0x682f
31.01.16 18:00:25,456 sandboxd[139]: ([431]) softwareupdated(431) deny system-fsctl 0x682f
31.01.16 18:00:37,090 WindowServer[178]: send_datagram_available_ping: pid 431 failed to act on a ping it dequeued before timing out.