Mac Unusable after Sierra 10.12.3 update

Hi, I have a Late 2012 iMac with Sierra. It was working perfectly until I updated it from 10.12.2 to 10.12.3. It hanged when updating (stayed in the white screen with the apple logo for hours) and since then the behaviour is consistently the following:

Works correctly for two system starts. On the third system start after shutdown my BootCamp partition disappears. If I try to run Disk Utility, nothing appears, just the rotating wheel.

Then, when I try to shutdown, the screen goes black and there is a rotating wheel in the middle. It stays there indefinitely. I force it to shutdown with the power button. Then, when I turn on the Mac, the behavior differs, sometimes it stays in the white screen with the apple logo and the progress bar indefinitely, sometimes (after a while) it goes to a black screen with a the mouse cursor only and can't do anything, sometimes it does go to the Finder (after a while, not the previous normal boot time) and my BootCamp partition remains disappeared and I cannot mount it. And the Disk Utility remains blank with the rotating wheel. If I try to shutdown, the same all over again, black screen with the rotating wheel indefinitely and after forcing shutdown and system restart, the same problems (hangs up in white screen, black screen, or slow start without BootCamp).

I tried NVRAM reset, SMC Reset, etc. but didn't work. The only way to solve this is booting into recovery mode (by the way, Disk Utility mode does work here, and the BootCamp partition appears correctly) and reinstalling the SW. But then I start the cycle again, two correct startups, third I lose BootCamp and cannot shutdown correctly, and start having problems booting. I tried wiping the system and performing a clean install with my time machine backup, but the same thing, starts up correctly a few times, and then the same issues. I have tried disconnecting all my USB devices and Thunderbolt External Drive, with no luck.

Nobody else is experiencing these issues? Please help!

Here's the output when I lose BootCamp and Disk Utilities won't load:

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 598.3 GB disk0s2

3: Apple_Boot 650.0 MB disk0s3

4: Microsoft Basic Data 401.0 GB disk0s4

And here´s the output from Etrecheck:

EtreCheck version: 3.1.5 (343)

Report generated 2017-03-05 10:16:25

Download EtreCheck from https://etrecheck.com

Runtime 1:38

Performance: Excellent

Click the [Support] links for help with non-Apple products.

Click the [Details] links for more information about that line.

Problem: Other problem

Hardware Information:ⓘ

iMac (27-inch, Late 2012)

[Technical Specifications] - [User Guide] - [Warranty & Service]

iMac - model: iMac13,2

1 2,9 GHz Intel Core i5 (i5-3470S) CPU: 4-core

24 GB RAM Upgradeable - [Instructions]

BANK 0/DIMM0

4 GB DDR3 1600 MHz ok

BANK 1/DIMM0

4 GB DDR3 1600 MHz ok

BANK 0/DIMM1

8 GB DDR3 1600 MHz ok

BANK 1/DIMM1

8 GB DDR3 1600 MHz ok

Bluetooth: Good - Handoff/Airdrop2 supported

Wireless: en1: 802.11 a/b/g/n

Video Information:ⓘ

NVIDIA GeForce GTX 660M - VRAM: 512 MB

iMac 2560 x 1440

System Software:ⓘ

macOS Sierra 10.12.3 (16D32) - Time since boot: about one hour

Disk Information:ⓘ

APPLE HDD WDC WD10EALX-408EA0 disk0 : (1 TB) (Rotational)

[Show SMART report]

disk0s1 (disk0s1) <not mounted> : 210 MB

Macintosh HD (disk0s2) / [Startup]: 598.35 GB (130.83 GB free)

disk0s3 (disk0s3) <not mounted> : 650 MB

disk0s4 (disk0s4) <not mounted> : 401.00 GB

USB Information:ⓘ

Apple, Inc. Keyboard Hub

Apple Inc. Apple Keyboard

Apple Inc. FaceTime HD Camera (Built-in)

Apple Inc. BRCM20702 Hub

Apple Inc. Bluetooth USB Host Controller

Thunderbolt Information:ⓘ

Apple Inc. thunderbolt_bus

Gatekeeper:ⓘ

Mac App Store and identified developers

Kernel Extensions:ⓘ

/Applications/Magican.app

[not loaded] com.magican.iokit.filemon (1.0.0 - SDK 10.7 - 2015-01-29) [Support]

[not loaded] com.magican.iokit.netmon (1.0.0 - SDK 10.7 - 2015-01-29) [Support]

/Applications/Smart Switch/SmartSwitch.app

[not loaded] com.devguru.driver.SamsungACMControl (1.4.42 - SDK 10.6 - 2017-02-19) [Support]

[not loaded] com.devguru.driver.SamsungACMData (1.4.42 - SDK 10.6 - 2017-02-19) [Support]

[not loaded] com.devguru.driver.SamsungComposite (1.4.42 - SDK 10.6 - 2017-02-19) [Support]

[not loaded] com.devguru.driver.SamsungMTP (1.4.42 - SDK 10.5 - 2017-02-19) [Support]

[not loaded] com.devguru.driver.SamsungSerial (1.4.42 - SDK 10.6 - 2017-02-19) [Support]

/Library/Extensions

[loaded] com.coriolis-systems.driver.OnlineHelper (522 - SDK 10.10 - 2017-02-20) [Support]

[not loaded] com.coriolis-systems.driver.Snapshot (100 - SDK 10.10 - 2017-02-20) [Support]

/System/Library/Extensions

[not loaded] com.FTDI.driver.FTDIUSBSerialDriver (2.2.16 - 2017-03-05) [Support]

[loaded] com.f-secure.kext.fsauth (0.5.0 - 2017-03-05) [Support]

~/Downloads/Hardware/WD Studio HDD/WD_Mac_Tools/Antiguo/WD +TURBO Installer (1-3-1).app

[not loaded] com.wdc.driver.USB_64HP (1.0.0 - SDK 10.6 - 2012-06-26) [Support]

~/Downloads/Hardware/WD Studio HDD/WD_Mac_Tools/Controladores/WD +TURBO Installer (1-3-7).app

[not loaded] com.wdc.driver.1394.64.10.9 (1.0.1 - SDK 10.9 - 2013-09-07) [Support]

[not loaded] com.wdc.driver.1394HP (1.0.11 - SDK 10.4 - 2013-09-07) [Support]

[not loaded] com.wdc.driver.1394_64HP (1.0.1 - SDK 10.6 - 2013-09-07) [Support]

[not loaded] com.wdc.driver.USB-64HP (1.0.3 - 2013-09-07) [Support]

[not loaded] com.wdc.driver.USB.64.10.9 (1.0.1 - SDK 10.9 - 2013-09-07) [Support]

[not loaded] com.wdc.driver.USBHP (1.0.14 - 2013-09-07) [Support]

System Launch Agents:ⓘ

[not loaded] 7 Apple tasks

[loaded] 174 Apple tasks

[running] 99 Apple tasks

System Launch Daemons:ⓘ

[not loaded] 40 Apple tasks

[loaded] 167 Apple tasks

[running] 105 Apple tasks

Launch Agents:ⓘ

[loaded] com.f-secure.relauncher.plist (2015-03-03) [Support]

[loaded] com.f-secure.trasher.plist (2015-03-03) [Support]

[loaded] com.google.keystone.agent.plist (2017-01-14) [Support]

[loaded] com.oracle.java.Java-Updater.plist (2017-02-20) [Support]

[not loaded] com.teamviewer.teamviewer.plist (2016-11-20) [Support]

[not loaded] com.teamviewer.teamviewer_desktop.plist (2016-09-19) [Support]

Launch Daemons:ⓘ

[loaded] com.adobe.fpsaud.plist (2017-01-30) [Support]

[loaded] com.f-secure.fsavd.dbhelper.plist (2015-03-03) [Support]

[running] com.f-secure.fsavd.plist (2015-03-03) [Support]

[loaded] com.f-secure.fsmac.firewall.plist (2015-03-03) [Support]

[loaded] com.f-secure.fsmac.fsupdated_guts2.plist (2015-03-03) [Support]

[loaded] com.f-secure.fsmac.licensetool.plist (2015-03-03) [Support]

[loaded] com.google.keystone.daemon.plist (2017-01-23) [Support]

[running] com.magican.castle.plist (2013-07-22) [Support]

[loaded] com.oracle.java.Helper-Tool.plist (2016-12-13) [Support]

[loaded] com.teamviewer.Helper.plist (2016-09-19) [Support]

[not loaded] com.teamviewer.teamviewer_service.plist (2016-11-20) [Support]

[loaded] com.tunabellysoftware.TGFanHelper.plist (2016-06-29) [Support]

User Login Items:ⓘ

Flux Aplicación

(/Applications/Flux.app)

fuspredownloader Aplicación Hidden

(~/Library/Application Support/.FUS/fuspredownloader.app)

Seguridad Total ONO Aplicación

(/Applications/Seguridad Total ONO/F-Secure Mac Protection.app)

Internet Plug-ins:ⓘ

Flip4Mac WMV Plugin: 3.0.0.126 - SDK 10.8 (2013-01-04) [Support]

FlashPlayer-10.6: 24.0.0.221 - SDK 10.9 (2017-03-05) [Support]

QuickTime Plugin: 7.7.3 (2017-01-13)

Flash Player: 24.0.0.221 - SDK 10.9 (2017-03-05) [Support]

JavaAppletPlugin: Java 8 Update 121 build 13 (2017-02-20) Check version

OfficeLiveBrowserPlugin: 12.2.7 (2010-10-15) [Support]

SharePointBrowserPlugin: 14.4.1 - SDK 10.6 (2014-04-09) [Support]

GarminGpsControl: 4.1.0.0 Release - SDK 10.7 (2013-10-09) [Support]

Silverlight: 5.1.50428.0 - SDK 10.6 (2016-09-04) [Support]

iPhotoPhotocast: 7.0 - SDK 10.8 (2012-11-03)

Safari Extensions:ⓘ

CustomReader - Canisbos Computing - http://canisbos.com/customreader (2015-09-25)

3rd Party Preference Panes:ⓘ

Flash Player (2017-01-30) [Support]

Flip4Mac WMV (2012-09-15) [Support]

FUSE for OS X (OSXFUSE) (2014-06-09) [Support]

Java (2017-02-20) [Support]

Perian (2011-07-23) [Support]

Time Machine:ⓘ

Skip System Files: NO

Mobile backups: OFF

Auto backup: YES

Volumes being backed up:

Macintosh HD: Disk size: 598.35 GB Disk used: 467.51 GB

Destinations:

G-DRIVE with Thunderbolt [Local]

Total size: 3.00 TB

Total number of backups: 47

Oldest backup: 1/5/16 8:45

Last backup: 1/3/17 0:39

Size of backup disk: Excellent

Backup size 3.00 TB > (Disk size 598.35 GB X 3)

Top Processes by CPU:ⓘ

9% kernel_task

5% mdworker(10)

5% WindowServer

2% hidd

2% Finder

Top Processes by Memory:ⓘ

1.31 GB kernel_task

344 MB Finder

319 MB com.apple.WebKit.WebContent(4)

221 MB WindowServer

221 MB mds_stores

Virtual Memory Information:ⓘ

18.67 GB Available RAM

14.55 GB Free RAM

5.33 GB Used RAM

4.12 GB Cached files

0 B Swap Used

Diagnostics Information:ⓘ

Mar 5, 2017, 08:19:52 AM Self test - passed

Mar 4, 2017, 11:10:51 PM /Library/Logs/DiagnosticReports/com.apple.WebKit.WebContent_2017-03-04-231051_[ redacted].cpu_resource.diag [Details]

/System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.We bKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent