Note: This article has been updated. Please see the solution at the bottom of the article.
My Dymo LabelWriter 400 Twin Turbo died last month. Sort of. There was no hardware failure. As far as I can tell, all the hardware components remain in fine working order. Neither has there been any major shift in technology that would make the printer obsolete. So, in some sense, the printer is still very much alive. It’s just that it won’t print labels.
The surprising source of the failure is that the Dymo Label software is incompatible with the latest version of OS X. The printer was working fine under OS X Mavericks 10.9.3. However, after I updated to OS X 10.9.4, I could no longer get any labels to print. Instead, an error message appeared that said the printer was “offline” or “not connected.”

The little printer that couldn’t: The Dymo LabelWriter fails to connect
You wouldn’t think that a minor OS X update, one that makes no mention of any printing-related changes, would precipitate this error. I certainly didn’t. That’s why, when the problem first appeared, I assumed it was a temporary glitch with the Dymo software—completely unrelated to the OS X upgrade. Such glitches had happened before… too many times before. So I went through the familiar drill of suggested fixes: unplugging and reconnecting the printer, deleting and reinstalling the driver, and ultimately completely reinstalling the Dymo software. This time, despite almost two hours of troubleshooting, the printer remained unresponsive.
Nothing at Dymo’s website offered further insight, so I initiated an online chat with Dymo support. The technician walked me through all the procedures I had already tried. He even introduced me to a couple of new ones, including how to remove the faceplate of the printer, so as to clean the printhead and rollers. Interesting… but of no help in this case. At the end of our efforts, and out of ideas, the technician did some “further research.” He returned to inform me that my “Twin Turbo has shown to be incompatible with whatever changes Apple made with 10.9.4. There is no fix at this time. If you can back down to 10.9.3, that should solve your issue.”
I couldn’t resist a tinge of snarkiness in my reply: “Now you tell me? Geez. Knowing that in advance would have saved us both a lot of time.” It would also have helped if Dymo posted this information to their website—or at least made certain that their technical support staff was aware of the matter.
As for his suggested solution, I had no intention of returning to OS X 10.9.3, possibly to be stuck there forever, just to keep a label printer working. I inquired as to the possibility that Dymo would soon release a software fix to address the conflict. The tech replied: “This printer has been out of production for some time, so it will depend on how complex an issue it turns out to be. Sometimes with the older printers, there is no fix. We will not know for awhile.”
In other words, don’t hold your breath waiting for a fix that might never come.
The tech went on to explain that Dymo’s current printers, the 450 series, do work fine with OS X 10.9.4. The problem was limited to just a “few older models,” of which mine was one. Another solution, therefore, would be to buy a new Dymo LabelWriter 450 Twin Turbo. Dymo was prepared to offer a 25 percent discount if I decided to go that route. As it turned out, the same printer was available at Amazon.com for a 50 percent discount ($100). So I declined Dymo’s not-so-generous offer and, with some reluctance, ordered the printer from Amazon. I can now confirm that the new printer does work with OS X 10.9.4; I’m printing labels again.
Summing up, Dymo has failed here in several significant respects.
To be fair to Dymo, I understand that a company cannot be expected to support older out-of-production hardware indefinitely. But this hardly seems to be a good example of when to opt out. The update from OS X 10.9.3 to 10.9.4 was a minor one. And, at least superficially, the differences between the Twin Turbo 400 and 450 seem small. It thus seems reasonable to assume that creating a fix would not be a significant drain on Dymo’s resources.
If my logic is incorrect here, and the required fix is somehow a big deal, I would at least expect Dymo to offer some explanation on their website. Instead, they have gone the opposite route. Not only does their site make no mention of any of this (at least not as of the time I was dealing with it), but their first line technical support staff has similarly been kept out of the loop. In addition to the misinformed online chat technician, the person behind the @DymoSupport Twitter account at first assured me that my printer should work with 10.9.4. After further discussion with higher-ups, he later acknowledged that “some devices are indeed incompatible.” Postings at Apple Support Communities offer similar stories.
Finally, Dymo’s suggested solutions of either downgrading the OS X software or overpaying for a new printer, seem unhelpful at best.
The end result is that a functioning printer is headed for the garbage heap (or perhaps to a Windows user) because Dymo is unable or unwilling to fix a software incompatibility. And it cost me $100 to replace a printer that ought to still be usable.
Update: I am pleased (and pleasantly surprised) to report that Dymo has fixed the incompatibility I’ve written about below. To get things working again, download the TwinTurboUpdater and follow its instructions. When I did this, my old LabelWriter was able to print again. Thanks Dymo!
One more thing: If you’ve updated to OS X Yosemite, you’ll also need to get the latest (8.5.2.95) version of the Dymo Label application.