Mavericks does not recognize SanDisk microSD XC 64GB. Please Help

Did you simply insert the SDXC card into the MacBook Pro card reader slot? There is FAT-32 and exFAT, but no FAT-21 spec.

Are these brand new cards, and what specifically does it say on the card. Is the card on this list?

It isn't Apple's responsibility to make OS X work with third-party card readers. It is the responsibility of the card reader manufacturer to keep their supporting software and/or hardware compatible with the most recent release of OS X. Most develop for Windows first, and then the Mac.

Check to see if that third-party card reader has updated software specifically for Mavericks. If it says 10.6+ or later, that isn't really a true assurance of Mavericks compatibility.

Here is an Apple Knowledge Base article: About the SD and SDXC card slot. Doesn't pertain to your external reader, but still potentially useful.

Good solve.

No, NOT A GOOD SOLVE.

I own a MacBook Pro 15-inch, Late 2011 running OSX 10.9.3. Owing to some unrelated issue Apple replaced the Motherboard some weeks ago, and all had been fine since then - up to moments ago that is.

Since I bought this Mac I have experienced a few problems, regardless of OS, when trying to read reliable name-brand top line SD cards from my pocket cameras. For some time before a recent OS change I found that insterting an SC card that was made by SanDisk that was no longer being read by my card reading slot, most but not all the way, caused the MacBook to mount the card. Up to a few days ago I had no problems with the Mac reading my SanDisk ULTRA 64GB 30MB/Sec. card.

Today I took the SanDisk card out of my camera, loaded it into the slot, AND MY MAC DOES NOT READ IT. I checked the Mac and it sees a Card Reader:

Built in SD Card Reader:

Vendor ID: 0x14e4

Device ID: 0x16bc

Subsystem Vendor ID: 0x14e4

Subsystem ID: 0x0000

Revision: 0x0010

Link Width: x1

Link Speed: 2.5 GT/s

But does not read the SD Card.

I put the SD Card back into the Canon pocket camera (Powershot S100), and the camera reads the saved images just fine.

I don't care if this card can be read by a Windows device or not (I ran Parallels just to access the card and download the new photos to my desktop - but my Mac simply does not see the SD Card now): the issue is my Mac is inconsistent - and that is not acceptable in any computer.

Appear to have solved the problem I mentioned above by resetting the System Management Controller (SMC). I browsed similar articles (USB Flash loading problems, etc.) and read someone else reset the SMC and that solved their problem, so I did that on my Mac. Note - I DID NOT reset PRAM.

Now I slide the SD card into the MacBook Pro slot, and iPhoto automatically launches and reads the photos on my card.

:-) Mac user again.

Bad followup news. This morning, a day or two after SD card slot started working, I had some device plugged into my USB Port of my MacBook Pro. I then inserted the SD card that I'd reported above was working (after SMC reset) - THE CARD IS NOT RECOGNIZED.

Back to square 1. Tried to reset SMC, but when following Apple instructions to put Mac to sleep I noted it takes several minutes after screen is black to actually hear internal parts (hard disk) go quiet. I'm not sure the SMC ever did reset now as I do not recall seeing the power adapter light blink.

Will have to call Applecare. :-(

Beyond frustrating. I'm having the same issue. With Apple, it used to be "It just works." That is no longer the case.

Well, I may have to eat the words I just posted above. First, I have a SanDisk Ultra PLUS 48 MB/s SDHC 32 GB.

I read another post where someone simply inserted the SanDisk into the slot and added as much additional pressure as they could. After reading numerous other posts and trying various recommendations--none of which made any difference--I tried this technique... and my McBook Pro instantly recognized the card. As long as I keep the pressure, it works.