I had this problem appear quite suddenly using Ubuntu 18.04 and Cubic revision 28. I had been using Cubic intensively for several days, working on iterations of a Live ISO for the Lenovo Yoga Book.
I ran a an apt-get upgrade followed by apt-get dist-upgrade and immediately ran into this problem trying to open one of my previous ISOs. I tried a stock Ubuntu ISO and a project directory from a previous (successful) iteration with the same result.
To get Cubic to work at all I have had to go back to Ubuntu 16.04 (in a VM). It works with all packages fully updated.
Interestingly, this setup creates an ISO which Etcher on the Mac says does not have a partition table and is not bootable. It boots in a VM but not when flashed to a USB. If I flash it using Rufus in Windows, which copies the ISO file-by-file rather than bit-by-bit and then has its own process for making the USB bootable, it boots fine.
I had this problem appear quite suddenly using Ubuntu 18.04 and Cubic revision 28. I had been using Cubic intensively for several days, working on iterations of a Live ISO for the Lenovo Yoga Book.
I ran a an apt-get upgrade followed by apt-get dist-upgrade and immediately ran into this problem trying to open one of my previous ISOs. I tried a stock Ubuntu ISO and a project directory from a previous (successful) iteration with the same result.
To get Cubic to work at all I have had to go back to Ubuntu 16.04 (in a VM). It works with all packages fully updated.
Interestingly, this setup creates an ISO which Etcher on the Mac says does not have a partition table and is not bootable. It boots in a VM but not when flashed to a USB. If I flash it using Rufus in Windows, which copies the ISO file-by-file rather than bit-by-bit and then has its own process for making the USB bootable, it boots fine.