On Ubuntu Mate 20.10 for about a week after upgrading from Ubuntu Mate 20.04.2. Upgraded from 20.04 LTS due to multiple issues with programs following a series of computer freezes while using FireFox 89, as some web sites (& plugins?) are very memory intensive.
All issues resolved thanks to distribution upgrade to 20.10. Then got a notice that 20.10 was at end of life cycle.
Started distribution upgrade process following How To Upgrade Ubuntu To 21.04
Note that Ji M.'s proposed method uses the gui update-manager How to Upgrade to Ubuntu 21.04 from Ubuntu 20.1
So following the first method above I started the process in a Tilda console. The process seem to be going just fine. Having just upgraded to 20.10 I realized this could take some time and I went to do something else while a waited for a prompt. When I came back there was no Tilda console although I had not closed it, and I was not able to reopen that Tilda session by using the F12 key as I had just done to start the process. No error messages.
I thought I might be able to get back into that Tilda console session (naïvely) and opened another console and tried to start Tilda from there. The screen capture no longer works whether from the gnome-screenshot app or through direct keyboard entry. Here is the output:
xian@Louiana:~$ tilda
Tilda encourtered an error: No such file or directory
Unable to set tilda's icon: /usr/share/pixmaps/tilda.png
Tilda has started. Press F12 to pull down the window.
Pressing F12 starts a new Tilda console, but no trace of the distribution upgrade process. I have not rebooted my machine yet for fear of trashing it, but maybe that won't trash it.
I don't if I should relaunch the distribution upgrade process or reboot the machine and then trying to relaunch the process, and if there issues with locked out files if restarting the machine in safe mode will change anything to restarting this dist upgrade process. Any suggestions please?