Catalina se bloquea al apagarse: "watchdog timeout: no checkins from watchdogd"

Tengo un Macbook Air 2017 con 8 GB de RAM y Intel Core i5 de doble núcleo a 1,8 GHz,

Después de actualizar a MacOS Catalina, mientras estoy usando mi portátil se congela y la pantalla se vuelve negra con un signo de carpeta con una interrogación en el centro parpadeando. Esto sucede a menudo y cuando reinicio mi portátil aparece este mensaje:

panic(cpu 2 caller 0xffffff7f87171ad5): userspace watchdog timeout: no successful checkins from com.apple.logd in 120 seconds
service returned not alive with context : unresponsive dispatch queue(s): com.apple.firehose.drain-mem 
service: com.apple.logd, total successful checkins since load (830 seconds ago): 72, last successful checkin: 120 seconds ago
service: com.apple.WindowServer, total successful checkins since load (800 seconds ago): 80, last successful checkin: 0 seconds ago

Backtrace (CPU 2), Frame : Return Address
0xffffff912644b720 : 0xffffff800611a65d 
0xffffff912644b770 : 0xffffff8006254a75 
0xffffff912644b7b0 : 0xffffff80062465fe 
0xffffff912644b800 : 0xffffff80060c0a40 
0xffffff912644b820 : 0xffffff8006119d27 
0xffffff912644b920 : 0xffffff800611a117 
0xffffff912644b970 : 0xffffff80068c1ad8 
0xffffff912644b9e0 : 0xffffff7f87171ad5 
0xffffff912644b9f0 : 0xffffff7f871717fa 
0xffffff912644ba10 : 0xffffff800685397e 
0xffffff912644ba60 : 0xffffff7f87170cfe 
0xffffff912644bb60 : 0xffffff800685cba3 
0xffffff912644bca0 : 0xffffff80062035e2 
0xffffff912644bdb0 : 0xffffff80061203c8 
0xffffff912644be10 : 0xffffff80060f6d15 
0xffffff912644be70 : 0xffffff800610db22 
0xffffff912644bf00 : 0xffffff800622c065 
0xffffff912644bfa0 : 0xffffff80060c1226 
      Kernel Extensions in backtrace:
         com.apple.driver.watchdog(1.0)[B6A95892-6C75-3CF5-A6CC-6D83F30FA1D5]@0xffffff7f87170000->0xffffff7f87178fff

BSD process name corresponding to current thread: watchdogd

Mac OS version:
19H2

Kernel version:
Darwin Kernel Version 19.6.0: Mon Aug 31 22:12:52 PDT 2020; root:xnu-6153.141.2~1/RELEASE_X86_64
Kernel UUID: 05D51A3D-3A87-3FF0-98C3-9CF3827A3EDD
Kernel slide:     0x0000000005e00000
Kernel text base: 0xffffff8006000000
__HIB  text base: 0xffffff8005f00000
System model name: MacBookAir7,2 (Mac-937CB26E2E02BB01)
System shutdown begun: NO
Panic diags file available: YES (0x0)

System uptime in nanoseconds: 838988891518
last loaded kext at 18297244763: org.virtualbox.kext.VBoxNetAdp 6.1.16 (addr 0xffffff7f89c9b000, size 28672)
loaded kexts:
org.virtualbox.kext.VBoxNetAdp  6.1.16
com.avast.PacketForwarder   2.1
org.virtualbox.kext.VBoxNetFlt  6.1.16
org.virtualbox.kext.VBoxUSB 6.1.16
com.avast.FileShield    4.0.0
org.virtualbox.kext.VBoxDrv 6.1.16
@fileutil   20.036.15
>AudioAUUC  1.70
>AGPM   111.4.4
>!APlatformEnabler  2.7.0d0
>X86PlatformShim    1.0.0
@filesystems.autofs 3.0
>!AHDAHardwareConfigDriver  283.15
>!AUpstreamUserClient   3.6.8
>!AHDA  283.15
>!AGraphicsDevicePolicy 5.2.6
@AGDCPluginDisplayMetrics   5.2.6
>!AHV   1
|IOUserEthernet 1.0.1
|IO!BSerialManager  7.0.6f7
>pmtelemetry    1
@Dont_Steal_Mac_OS_X    7.0.0
>!A!IBDWGraphics    14.0.7
>AGDCBacklightControl   5.2.6
>!A!ISlowAdaptiveClocking   4.0.0
>!ABacklight    180.3
>ACPI_SMC_PlatformPlugin    1.0.0
>!AMCCSControl  1.14
>!A!IBDWGraphicsFramebuffer 14.0.7
>!AFIVRDriver   4.1.0
>eficheck   1
>!AThunderboltIP    3.1.4
>!ACameraInterface  7.6.0
>!ALPC  3.1
>!ASMCLMU   212
|IO!BUSBDFU 7.0.6f7
|SCSITaskUserClient 422.120.3
>!U!SCoexistentDriver   489.120.1
>!UCardReader   489.120.1
>!ATopCaseHIDEventDriver    3430.1
>!AFileSystemDriver 3.0.1
>!AVirtIO   1.0
@filesystems.hfs.kext   522.100.5
@!AFSCompression.!AFSCompressionTypeDataless    1.0.0d1
@BootCache  40
@!AFSCompression.!AFSCompressionTypeZlib    1.0.0
@filesystems.apfs   1412.141.1
>!AAHCIPort 341.140.1
>AirPort.BrcmNIC    1400.1.1
@private.KextAudit  1.0
>!ASmartBatteryManager  161.0.0
>!ARTC  2.0
>!AACPIButtons  6.1
>!AHPET 1.8
>!ASMBIOS   2.1
>!AACPIEC   6.1
>!AAPIC 1.7
$!AImage4   1
@nke.applicationfirewall    303
$TMSafetyNet    8
@!ASystemPolicy 2.0.0
|EndpointSecurity   1
|IOUSBUserClient    900.4.2
@kext.triggers  1.0
>DspFuncLib 283.15
@kext.OSvKernDSPLib 529
>!AGraphicsControl  5.2.6
|IOAVB!F    850.1
@!AGPUWrangler  5.2.6
|IOSlowAdaptiveClocking!F   1.0.0
>!ABacklightExpert  1.1.0
|IONDRVSupport  576.1
>IOPlatformPluginLegacy 1.0.0
>!ASMBus!C  1.0.18d1
@!AGraphicsDeviceControl    5.2.6
|IOAccelerator!F2   438.7.3
>X86PlatformPlugin  1.0.0
>!AThunderboltEDMSink   4.2.3
>!AThunderboltDPOutAdapter  6.2.6
>IOPlatformPlugin!F 6.0.0d8
>!ASMBusPCI 1.0.14d1
>!AHDA!C    283.15
|IOGraphics!F   576.1
|IOHDA!F    283.15
@plugin.IOgPTPPlugin    840.3
|IOEthernetAVB!C    1.1.0
|Broadcom!BHost!CUSBTransport   7.0.6f7
|IO!BHost!CUSBTransport 7.0.6f7
|IO!BHost!CTransport    7.0.6f7
>usb.IOUSBHostHIDDevice 1.2
>usb.!UHub  1.2
|IOUSBMass!SClass   4.0.4
>usb.cdc    5.0.0
>usb.networking 5.0.0
>usb.!UHostCompositeDevice  1.2
>!AHS!BDriver   3430.1
>IO!BHIDDriver  7.0.6f7
|IO!B!F 7.0.6f7
|IO!BPacketLogger   7.0.6f7
>!AMultitouchDriver 3440.1
>!AInputDeviceSupport   3440.8
>!AHIDKeyboard  209
>!AHSSPIHIDDriver   59
|IOAudio!F  300.2
@vecLib.kext    1.2.0
|IOSerial!F 11
|IOSurface  269.11
@filesystems.hfs.encodings.kext 1
>!AXsanScheme   3
|IOAHCIBlock!S  316.100.5
|IOAHCI!F   290.0.1
>!AThunderboltDPInAdapter   6.2.6
>!AThunderboltDPAdapter!F   6.2.6
>!AThunderboltPCIDownAdapter    2.5.4
>!AThunderboltNHI   5.8.6
|IOThunderbolt!F    7.6.1
|IO80211!F  1200.12.2b1
>mDNSOffloadUserClient  1.0.1b8
>corecapture    1.0.4
|IOSkywalk!F    1
>!AHSSPISupport 59
>!A!ILpssSpi!C  3.0.60
>!A!ILpssGspi   3.0.60
>!A!ILpssDmac   3.0.60
>!A!ILpssI2C    3.0.60
>usb.!UXHCIPCI  1.2
>usb.!UXHCI 1.2
>usb.!UHostPacketFilter 1.0
|IOUSB!F    900.4.2
>!AEFINVRAM 2.1
>!AEFIRuntime   2.1
|IOSMBus!F  1.1
|IOHID!F    2.0.0
$quarantine 4
$sandbox    300.0
@kext.!AMatch   1.0.0d1
>DiskImages 493.0.0
>!AFDEKeyStore  28.30
>!AEffaceable!S 1.0
>!ASSE  1.0
>!AKeyStore 2
>!UTDM  489.120.1
|IOSCSIBlockCommandsDevice  422.120.3
>!ACredentialManager    1.0
>KernelRelayHost    1
>!ASEPManager   1.0.1
>IOSlaveProcessor   1
|IOUSBMass!SDriver  157.140.1
|IOSCSIArchitectureModel!F  422.120.3
|IO!S!F 2.1
|IOUSBHost!F    1.2
>!UHostMergeProperties  1.2
>usb.!UCommon   1.0
>!ABusPower!C   1.0
|CoreAnalytics!F    1
>!AMobileFileIntegrity  1.0.5
@kext.CoreTrust 1
|IOReport!F 47
|IOTimeSync!F   840.3
|IONetworking!F 3.4
>!AACPIPlatform 6.1
>!ASMC  3.1.9
>watchdog   1
|IOPCI!F    2.9
|IOACPI!F   1.4
@kec.pthread    1
@kec.Libm   1
@kec.corecrypto 1.0

He ido a apple y me han borrado el portátil y reinstalado macOS Catalina pero el problema persiste. ¿que hago?