Lexar Professional ExpressCard Compact Flash Reader Driver for MacOS 10.10, 10.11, 10.12, and 10.13

February 2018 update: This adapter still seems to work for me in 10.13.3 using Sonnet’s latest driver.

November 2017 update: Martin wrote in below to share that this worked for 10.12 as well.

I have a Lexar Professional ExpressCard Compact Flash Reader, model number LRWEXPP-7000.

Lexar’s latest drivers do not work for MacOS 10.10 and 10.11 because they way they must be installed has changed.

However, Andrew Jung, a reviewer on Amazon, left a very helpful tip on the product’s page a few days ago. Read on for a possible solution.

The drivers that Lexar uses are old and out of date and will not install on 10.10 and 10.11 because Apple now requires that all kernel extensions have a proper developer signature. Lexar’s response about that is:

“Thank you for contacting Lexar. Unfortunately, we have no plans on releasing an update for that reader since things have been leaning more towards Thunderbolt series and USB 3.0. I apologize for the inconvenience but you can check out our newer readers”

But I don’t take “No” for an answer and didn’t give up I figured out that Lexar’s reader uses an ATA bridge and drivers made by JMicron. I tried there but didn’t find anything to download on their site. Then I really wished that I had bought the Sonnet Technologies “Pro Dual Compact Flash ExpressCard/34 adapter” instead. I saw one for auction and was going to bit, but I figured that I should try to see if their software would install before I try to get the Sonnet ExpressCard.

I went to Sonnet Technologies’ website and download the driver for the “Pro Dual Compact Flash ExpressCard/34 adapter” (the 1.0.6 version I downloaded was released Nov 2014) and tried to install it. It succeeded in installing, which was good, but suddenly my Lexar Professional Express Card Compact Flash Reader’s activity light started blinking and my CF mounted on my MacBook Pro’s desktop that is running El Capitan.

The Sonnet driver tries to first install the JMicron driver and fails but then goes on to install CFRW2X-E34.kext instead and it works for my Lexar ExpressCard! It’s also got a nice Finder icon of a CF card instead of the generic orange one and in the System Information (Profiler) it properly identifies what brand type of card is installed.

Hope that is helpful for Mac users out there. In this case persistence paid off and I now can continue to use this reader for the foreseeable future.
I’m super happy now.

Use at your own risk, but I can confirm that this works just fine for me. Thanks, Andrew!

PS. If you’re reading this, this probably just saved you a whole bunch of money, so please consider donating a few bucks to a charity like Friends of San Francisco Animal Care & Control. They do truly amazing work.

2018-02-13T22:49:27+00:00 September 25th, 2015|10 Comments


  1. Jose September 27, 2015 at 4:19 pm

    Thanks, it worked perfectly. I was almost giving up.

  2. Chris Gagne September 27, 2015 at 4:52 pm

    Glad I could help! 🙂

  3. Frank Nuernberger October 13, 2015 at 12:17 pm

    Thank you very much!!! It really works on my MBP 15 Retina! These guy at Lexar don’t make me want to spend money on a new reader.

  4. Richard Mann November 18, 2015 at 4:30 am

    Well done Chris!
    I would have thought Lexar have enough resources to resolve this issue.
    They’re keen enough to sell us their products!

  5. Stuart January 10, 2016 at 3:59 pm

    You legend! To say this issue was giving me the S%$&S is an understatement. What an enormous pain that neither Apple or Lexar can address these issues.
    You’ve made my month.

  6. Jay Taylor February 13, 2016 at 12:53 am

    Chris, You da man!
    I was bummed my old Apiotek Express Card Adapter was toast and I was going to have to rely on painfully slow transfers via USB. This driver has it working again under El Capitan.

  7. Sascha August 12, 2017 at 12:45 pm

    Works also for the Delock Express Card to Compact Flash on El Capitan.
    Thanks a lot!

  8. Martin November 1, 2017 at 2:40 pm

    Thanks for the tip this works for 10.12 too!

  9. Chris Gagné November 1, 2017 at 4:23 pm

    Awesome, thanks for the tip!

  10. Chris Gagné November 1, 2017 at 4:23 pm

    Thank you!

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