Out of nowhere, the boot login/decryption screen started to become unresponsive. Fortunately, the screen is responsive for about a second every minute (or so). This way I can still type in my password at 2 chars / min (*o*) and log in.

Once logged in, everything is fine. Non-boot logging screens are not affected. The same is the case when booting from an older Mac OS via USB. The closest related problem I could find was macOS Sierra boot problem related to Apple SD Card reader driver.

But the described behavior is not a perfect match. However, the last thing I did before the issue appeared was to copy a file onto a SD card I had never connected previously (I always have a built-to-fit SD card connected).


  • Mac OS 11.6.7 (internal, last updated after appearance of bug) & Mac OS 10.15 (external, USB)
  • MacBookAir6,2
  • SSD exchanged for NVMe (not fully supported by hardware)
  • FileVault active

Full list of symptoms:

  • Time between boot sound and apple logo increased from seconds to minutes
  • Duration apple logo is shown also increased from seconds to minutes
  • Boot login screen unresponsive/frozen for about a min at a time
  • Boot login screen responsive for about a second after every unresponsive min
  • Text field caret frozen
  • Trackpad inputs during unresponsive time lead to expected update of the position of the cursor during the responsive second
  • Keyboard inputs only registered during responsive second (major issue as typing a long password then takes forever)

Attempted fixes:

  • Reset SMC
  • Reset PRAM
  • Disabling FileVault
  • Disabling Bluetooth
  • Fix disk in recovery mode (no errors found)
  • Connecting USB keyboard does not help (no power at that stage)

I am looking into possible offending kexts and SD card reader drivers at the moment but as rebooting takes at least 15 min, progress is slow and frustrating...

UPDATE: Rebooting without SD card gives a responsive login screen! So the SD cardreader is indeed the culprit. Now I only need a way to fix it on the sw side...

1 Answer 1


So, the solution for me was to use the Apple Disk Utility app to run the First Aid on the offending SD card. I am not sure at which level it makes more sense to run First Aid (Card read / Container / APFS volume), I did all 3 and the issue is now gone (the login screen is responsive). Thank god this did not need a hardware exchange as suggested in macOS Sierra boot problem related to Apple SD Card reader driver

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