Doubling clicking the appimage did not work so I tried the following commands
chmod +x .appimage
sudo ./.appimagebut it gives me the error
dlopen(): error loading libfuse.so.2 AppImages require FUSE to run. You might still be able to extract the contents of this AppImage if you run it with the --appimage-extract option. See for more information
but Fuse is installed in my system.
apt-cache policy libfuse2 libfuse2: Installed: 2.9.9-3 Candidate: 2.9.9-3 Version table: *** 2.9.9-3 500 500 focal/main amd64 Packages 100 /var/lib/dpkg/status
I'm on Ubuntu 20.04
101 Answer
According to the corresponding issue the downloaded Appimage file is a 32-bit version
balenaEtcher-1.5.121-ia32
while the installed library is 64-bit
apt-cache policy libfuse2 ... 500 focal/main amd64 Packages
Unfortunately the error message from the Appimage code is insufficient:
dlopen(): error loading libfuse.so.2 AppImages require FUSE to run. ...
It doesn't tell what version of the library the dlopen() call searched for or where it searched for the library. This is a bit confusing when you see that the library libfuse.so.2 is installed on your system, contrary to the error message.
Running the Appimage with strace might show that it searches for the library in directories for 32-bit libraries.
So in case of this error you should check if the architecture of the Appimage file matches your system's architecture.