Yesterday I updated my 2016 Cactus to the latest version (and probably the last) following the notes by @cactusRipCurl2016
Decided to make a step-by-step guide for people who feel less confident in their tech knowledge. Hopefully some of you will find it helpful - and once again props to @cactusRipCurl2016 and everyone before him who shared links and tips on how it's done.
Just to be clear, this is a totally unofficial guide! The procedure is fairly simple but as with all firmware updates, there is a very slight chance something may go wrong. Use at your own risk!
Download the latest firmware (the only one from 2018) from this link: https://mega.nz/#F!ntEhlLTR!2TjMy1eo-Yf9q13MbVrnYA
The file you downloaded comes in an archive, you have to unzip it first. If you don't have software for that, download and install 7-Zip, it's free: https://www.7-zip.org/
There is only one folder in the .7z file - unzip it somewhere you can find it. You will transfer the whole folder on a USB stick later.
Insert a USB stick. If you have files on it - transfer them to your PC or delete them, as we have to format the drive so that the car can read it. All files currently on the drive will be lost when formatting it. Once you are done, go to This PC (or My Computer in earlier versions of Windows) and find the USB drive you have inserted. If you are unsure which one it is, just unplug it and insert it again, watch what will show up there. In my case, it is USB Drive (F:).
Right click on the drive icon, select "Format...". In the new popup window, change the file system to be FAT32 and Allocation unit size to be "Default allocation size". Here is what it should look like:
Some USB drives may not work, as reported by other people. You need a drive that is 2GB+ in size, it should be fairly easy to find another one to use if yours is not recognized by the car.
Drag and drop the folder from step 2 in the newly formatted drive. Wait until the files are transferred (it would take about a minute depending on your hardware). After the file transfer finishes, this is what your USB drive should look like:
Unplug it (preferably ejecting it first via the right click menu on the drive icon) and go to your beloved Cactus.
Start the car, once the infotainment system loads, press and hold the Settings button for a few seconds until the service screen shows up. This is what it looks like:
This will show you your current firmware version and the release date. Needless to say, if you are already on the latest version, no need to update at all.
Insert the USB stick you configured. If the car recognizes there is an update file on it, it will scan it. That may take a while, but pay attention. Once the scan is done, a new message will be displayed prompting you to update. This is what it looks like:
Verify that a new version of the software will be installed and tap on Yes.
Note that this is a timed popup, it will only stay for a couple of seconds. If you miss it, unplug the USB stick and insert it again. You will have to wait for the files to be scanned again.
Make sure you have enough fuel to keep the engine running while the update takes place. As reported, it may take up to about 30 minutes to complete. In my case it only took about 6-7 minutes. It is very important to keep the engine running. Just in case, you may want to disable the Stop/Start system before you begin as well.
Your car will restart the infotainment system a few times while updating, this is normal. This is what the screen looks like while updating:
Once the update is done, the car will once again scan the files on the USB stick. A popup will appear asking if you want to update when the scan is completed, but this time the current version number and the update version number (below it) will be the same. At this point select No and unplug the USB stick, we are done. Turn the engine off, wait for a couple of minutes, then start the car. Go to the service screen from step 6 and verify that you now have the latest version of the firmware.