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I was about to give up trying to update my XT to 2026.30 (US). I installed the latest Express, restarted my Mac and the GPS numerous times, even reinstalled Express after removing all traces from preferences and caches, but Express kept saying there was an error while installing the update. It never got past the first few seconds after contacting the server.

I concluded that the problem was in the XT, because when I asked Express to install the map to my computer, it did so quickly, without error, even though the map had not been installed on the GPS (but it was connected via USB). It showed up just fine in Basecamp.

Having decided the XT was the problem, I was very reluctant to do a factory reset in case it stopped working altogether -- it was still operating properly with 2026.10. I was also nervous about doing the update over WiFi in case it failed, or corrupted the map. But finally I decided to try it, despite the very pessimistic 3-hour time estimate. WiFi actually took only about 25 minutes and the XT is working fine. Whew! More fun with Garmin.

-dan

@danham , the last time I updated the map via wifi, Express didn't see that the new map was installed and wanted to update. It was as if Express was only aware of the version it last installed and not actually reading what was on XT. IIRC, I let Express do an update, ended up with two on the XT, and then had to clean up that mess. I no longer remember the details other than avoiding wifi. I don't know what I would have done in your case since wifi has been a no-go for me since me debacle.

As I said, more fun with Garmin. As I ponder this mess, I have to wonder if the mandatory firmware update that Express did before starting to throw map update errors is to blame. Does anyone know if it is possible to reinstall the latest firmware? Does that require a full reset?

-dan

I once downgraded my firmware. These are my notes-to-self on the process (created Dec 2022):

Zumo XT firmware rollback or manual installation:

Instructions on how to rollback a firmware update or install firmware from the SD card is in this forum post:
https://www.zumouserforums.co.uk/app.php/ZXT-P85

Previous firmware files are stored in C:\ProgramData\Garmin\CoreService\Downloads\PrimaryFirmware

This \Downloads directory on my new Win11 machine contains a \Firmware subdirectory but not a \PrimaryFirmware subdirectory. Perhaps because I have only updated the firmware once with this machine????

FWIW, there is a note on the 'how to' page that says the option B02 (install from SD card) did not work but I had success with it.

As for whether it will reset the XT, I don't specifically recall but that was not a concern for me because I keep my XT very lean with only about a dozen local routes kept on it, originals of which are on the SD card.

I often have errors when transferring large amounts of data from my PC to the XT via USB unless I connect through a USB hub. Map updates are a common cause of errors when I forget the hub, so are gigabytes of music at a time. Smaller amounts of data like a time zone update, or a few .gpx files are not a problem with a direct cable connection.

danham wrote: Tue Jan 13, 2026 7:29 pm I was also nervous about doing the update over WiFi in case it failed, or corrupted the map. But finally I decided to try it, despite the very pessimistic 3-hour time estimate. WiFi actually took only about 25 minutes and the XT is working fine. Whew! More fun with Garmin.

-dan

Thanks for that. Having moved from Windows to Linux I'll be relying on that method in future!

lkraus wrote: Wed Jan 14, 2026 2:47 am I often have errors when transferring large amounts of data from my PC to the XT via USB unless I connect through a USB hub. Map updates are a common cause of errors when I forget the hub, so are gigabytes of music at a time. Smaller amounts of data like a time zone update, or a few .gpx files are not a problem with a direct cable connection.

I wonder why the hub makes a difference. I had always directly connected to my HP Pavilion laptop without a problem. I say "had" because I have a Lenovo now and use a hub for convenience in the new space where it sits. I always use the Garmin cable that came with my XT. Garmin could have been a bit more generous with its length though.

I don't know what the hub does, I only tried it because I knew many Mac users could not connect at all without a hub. Maybe it slows down the transfer, or maybe it serves as a regulator to keep the transmit/receive signals in sync? Garmin tends to use old tech which can't keep up with newer computers. I really would have expected the XT to use a USB-C connection and support exFAT microSD cards.

lkraus wrote: Wed Jan 14, 2026 2:47 pm I really would have expected the XT to use a USB-C connection and support exFAT microSD cards.

Maybe not USB-C considering the PC I had when I bought my XT did not have USB-C ports. Including a USB-C to USB-A adapter would have been a nice touch at a minimal additional cost. As for the lack of support for exFAT formatted SD cards, unfathomable!

Peobody wrote: Wed Jan 14, 2026 1:01 am I once downgraded my firmware. These are my notes-to-self on the process (created Dec 2022):

Zumo XT firmware rollback or manual installation:

Instructions on how to rollback a firmware update or install firmware from the SD card is in this forum post:
https://www.zumouserforums.co.uk/app.php/ZXT-P85

Previous firmware files are stored in C:\ProgramData\Garmin\CoreService\Downloads\PrimaryFirmware...

On a Mac, I assume the firmware file would live in the hidden folders under ~Library/Application Support/Garmin/Express. I can't find any such update file anywhere on my Mac. However, the file apparently stays on the XT after an update, so I now have B348400.update on my computer. It presumably contains v6.70, so I can't downgrade, but maybe I can reinstall 6.70?

But until or unless the XT misbehaves I think I'll hold off on further experiments.

-dan