I got this error today after downloading the latest Mac version of Etcher, when trying to use an ISO for Pop_OS! named “pop-os_22.04_amd64_intel_52.iso”. I renamed the file to just popos.iso and it worked, and flashed successfully. No admin rights changes, nothing else.
Same issue here. with newest version 2.1.0 and Fedora Linux 41. Then, I use .rpm file instead and got problem solved.