Hello @petraviva ,
Welcome to Poly Community.
Thank you for sharing this.
Many products use step upgrade approach, meaning you cannot jump to latest FW build if you are missing intermediary builds. So Please raise a ticket with our Headset and Personal Devices support team so that they can see if it is possible to get you missing updates first. Also it will be a good Idea to always use native USB connection of computer (avoid using USB splitters or docking stations) to perform firmware updates. And try with other PC too to see if that allows the update to go through.
Troubleshooting or providing support via the community is outside the scope for myself as a Poly employee.
Please raise a ticket with our support team and you will need to provide the following:
• Error screenshots.
• Video of issue if possible as it will help visualize the issue.
• -Serial number of unit and current firmware version of headset/speaker/USB dongle when issue is noticed
• HUB version and OS version in use