Hi there. I installed Mavericks on a late 2012 iMac previously on Mountain Lion this afternoon and half an hour into using the new osx a strange problem unfolded: 1. All the Folders, the HD icon, and the ability to click on the desktop suddenly disappeared. The dock is still there, the menu bar only appears when i click on an app, and spotlight still allows me to find and open things which are on my HD, such as documents and pictures. 2. The following message is on an infinite crash loop and repeats each time OK is pressed: Process: Finder  Path: /System/Library/CoreServices/Finder.app/Contents/MacOS/Finder Identifier: Finder Version: ??? Code Type: X86-64 (Native) Parent Process: launchd  Responsible: Finder  User ID: 501 Date/Time: 2013-10-23 00:31:58.002 -0700 OS Version: Mac OS X 10.9 (13A603) Report Version: 11 Anonymous UUID: 487C41C5-20B3-25FF-2B9D-AAB4355CA8EA Crashed Thread: 0 Exception Type: EXC_CRASH (Code Signature Invalid) Exception Codes: 0x0000000000000000, 0x0000000000000000 VM Regions Near 0x7f7fb970ed30 (cr2): VM_ALLOCATE 0000000107d31000-0000000107d32000 [ 4K] rw-/rwx SM=ALI --> STACK GUARD 00007fff544c8000-00007fff57cc8000 [ 56.0M] ---/rwx SM=NUL stack guard for thread 0 Thread 0 Crashed: 0 dyld 0x00007fff649a1028 _dyld_start + 0 Thread 0 crashed with X86 Thread State (64-bit): rax: 0x000000000000000d rbx: 0x0000000000000000 rcx: 0x0000000000000000 rdx: 0x0000000000000000 rdi: 0x0000000000000000 rsi: 0x0000000000000000 rbp: 0x0000000000000000 rsp: 0x00007fff584c7d70 r8: 0x0000000000000000 r9: 0x0000000000000000 r10: 0x0000000000000000 r11: 0x0000000000000000 r12: 0x0000000000000000 r13: 0x0000000000000000 r14: 0x0000000000000000 r15: 0x0000000000000000 rip: 0x00007fff649a1028 rfl: 0x0000000000000201 cr2: 0x00007f7fb970ed30 Logical CPU: 0 Error Code: 0x020000f4 Trap Number: 133 Binary Images: 0x7fff649a0000 - 0x7fff649d3817 dyld (???) <D1DFCF3F-0B0C-332A-BCC0-87A851B570FF> /usr/lib/dyld External Modification Summary: Calls made by other processes targeting this process: task_for_pid: 0 thread_create: 0 thread_set_state: 0 Calls made by this process: task_for_pid: 0 thread_create: 0 thread_set_state: 0 Calls made by all processes on this machine: task_for_pid: 233 thread_create: 0 thread_set_state: 0 VM Region Summary: ReadOnly portion of Libraries: Total=288K resident=260K(90%) swapped_out_or_unallocated=28K(10%) Writable regions: Total=8492K written=0K(0%) resident=12K(0%) swapped_out=0K(0%) unallocated=8480K(100%) REGION TYPE VIRTUAL =========== ======= STACK GUARD 56.0M Stack 8192K VM_ALLOCATE 8K VM_ALLOCATE (reserved) 48K reserved VM address space (unallocated) __DATA 252K __LINKEDIT 80K __TEXT 208K mapped file 6068K shared memory 4K =========== ======= TOTAL 70.5M TOTAL, minus reserved VM space 70.5M Model: iMac13,1, BootROM IM131.010A.B05, 4 processors, Intel Core i5, 2.9 GHz, 8 GB, SMC 2.9f5 Graphics: NVIDIA GeForce GT 650M, NVIDIA GeForce GT 650M, PCIe, 512 MB Memory Module: BANK 0/DIMM0, 4 GB, DDR3, 1600 MHz, 0x02FE, 0x45424A3431554638424455352D474E2D4620 Memory Module: BANK 1/DIMM0, 4 GB, DDR3, 1600 MHz, 0x02FE, 0x45424A3431554638424455352D474E2D4620 AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0xF4), Broadcom BCM43xx 1.0 (188.8.131.52.22) Bluetooth: Version 4.2.0f6 12982, 3 services, 23 devices, 1 incoming serial ports Network Service: Ethernet, Ethernet, en0 Serial ATA Device: APPLE HDD HTS541010A9E662, 1 TB Serial ATA Device: APPLE SSD SM128E, 121.33 GB USB Device: Hub USB Device: Hub USB Device: BRCM20702 Hub USB Device: Bluetooth USB Host Controller USB Device: Hub USB Device: FaceTime HD Camera (Built-in) Thunderbolt Bus: iMac, Apple Inc., 23.4 3. I've attempted to change users, and create new users, but the issue persists on each of these. 4. A hardware test on startup reveals the following issue: error: 4HDD/30/40000005: SATA (0,0) 5. I'm unable to start the computer in safemode. Pressing down shift opens the start-up progress bar on the gray screen, but after that finishes the computer merely restarts and loads in regular mode. 6. The only additional install I did today outside of Mavericks was a third-party software called Docker which allows you to change the appearance of the dock. Really confused and frustrated as to what to do, and would be extremely grateful for any help or advise any one has. Thanks kindly in advance! Agahno.