I faced similar problem with Gutsy RC installation - I selected Firefox in the list of applications to migrate, and got the same error message. Clicking "Go Back" unmounted the partition apparently, but did not continue with the installation. The installation progress dialog just disappears, without any success/error messages.
Since there were no errors, I thought maybe installation was successful. However, on rebooting I didn't see the Grub menu. I ran the installation again and this time chose "Continue" on the error. The installation continued and I saw the progress bar completing after doing a lot of more things. Finally I got the completion message and reboot popup, so this time I knew that everything was fine. Rebooting got me to the Grub menu now. -- [gutsy] failed to unmount migrationassistant https://bugs.launchpad.net/bugs/135149 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
