I need to update to the last thunderbold3 firmware, but when I click ok on the warning message, the result is another message that say: "you need to install thunderbold 3 driver before run update."
But I just have thunderbold driver installed on my system... How I can do ?
Have you confirmed you're on the LATEST Thunderbolt driver (220.127.116.115, A03 as of this writing) and also on the latest BIOS (1.3.4, as of this writing)? Did you restart after installing those?
Tried to update and was told firmware is up to date version 21.0; I cannot see 1.3.4 in the Thunderbolt software settings! Driver is 18.104.22.168
Version 1.3.4 is your system BIOS/firmware, nothing to do with Thunderbolt, but some Thunderbolt firmware updates won't install unless the SYSTEM's firmware is at a certain level. However, looking at the support.dell.com Drivers page for your XPS 15 9560, Thunderbolt firmware NVM 21 is the latest version anyway, so it appears you don't need to update anything.
Thank you! I think confusion has been caused by Dell dating the firmware update 8 Aug 2017 as I installed same quite a while ago; presumably the OP has had similar experience believing it to be an update when in fact file appears to have had just a date update?
Yes, I've seen this odd behavior of previously released firmware getting newer dates. I wonder if the date updates if Dell simply updates the description page with new information or something? Still, if memory serves, trying to install a Thunderbolt firmware update you don't need should return a "Thunderbolt firmware is up to date" message, not a failure.