10.10.3 and no SD cards won't mount or are Read-Only

[pubwvj]

All of my SD cards are suddenly giving this erroneous Read-Only message. It started wit the 10.10.3 update of my MacBook Pro. Before that they worked fine. I have cards from different brands and sizes. The problem is with the MacOS X update having a bug. Older computers that do not have the 10.10.3 update do not have the problem mounting, reading or writing to these cards. All of the cards have their tabs in the unlocked position and worked before.

Solutions?

Known 10.10.3 bug?

 

[chrfr]

All of my SD cards are suddenly giving this erroneous Read-Only message. It started wit the 10.10.3 update of my MacBook Pro. Before that they worked fine. I have cards from different brands and sizes. The problem is with the MacOS X update having a bug. Older computers that do not have the 10.10.3 update do not have the problem mounting, reading or writing to these cards. All of the cards have their tabs in the unlocked position and worked before.

Solutions?

Known 10.10.3 bug?

It's most likely dust in the slot near the switch sensor. I found this video that suggests putting the R/W switch about midway between read-only and R/W: https://www.youtube.com/watch?v=nehn7mh81vs
I would think you could gently clean that area with a toothpick or some other non-metallic tool too.

 

[pubwvj]

Thank you for your reply. I looked at the video and tried both cleaning and half way positioning. Unfortunately those do not resolve the issue. This problem began all of a sudden with the upgrade from 10.10.2 to 10.10.3 and affects _many_ cards not just one. This is a software bug in 10.10.3. I've reported it to Apple. Hopefully they'll do a fix soon.

 

[chrfr]

Thank you for your reply. I looked at the video and tried both cleaning and half way positioning. Unfortunately those do not resolve the issue. This problem began all of a sudden with the upgrade from 10.10.2 to 10.10.3 and affects _many_ cards not just one. This is a software bug in 10.10.3. I've reported it to Apple. Hopefully they'll do a fix soon.

As I'd mentioned in the 10.10.3 thread, I have SD cards I've used in several Macs with 10.10.3 and all cards and Macs work as they did before. Do you have another startup disk that isn't on 10.10.3 that you could use to test? It's not impossible that something broke around the same time that 10.10.3 went in.
Edit: you could boot into internet recovery (not regular recovery as that will have been updated to 10.10.3) to see if the card works in that version of Disk Utility.