Another way is to close Firefox then in the terminal move the old profile out of the way:

Then try running Firefox again.

But didn't you say that this was going to be a server? Firefox is a desktop application and a graphical one at that.

Sorry, I get the attached.

Sorry, that's not what I typed. You have an extra space in there. Fortunately it did not work.

Please increase the font-size on your browser and re-examine what I typed.

I've run the correct command. But I still get the attached

Any help?

When you moved the directory, did you follow these exact steps?

1. stop firefox
2. move the directory out of the way
3. start firefox

Alternately, what were your results when you tried the same using Habitual's advice about using Firefox's profile manager?
https://support.mozilla.org/en-US/kb...refox-profiles

I must admit I am deeply confused as to what a graphical interface and Firefox especially are doing on a server. Is this really a server or is it a desktop with a server application or two? Either is ok but you do have to decide.

Yes, I did follow the steps. This is a server and not a desktop.

How did it get a desktop application like Firefox and the desktop graphical interface that Firefox runs on top of?

I did originally finish the setup of everything of the server, including also Firefox. Do you think I may have to re-do the setup, like to re-create the server OS?

It might be easier to start from a fresh installation. You can practice / test your data and configuration backup and restoration procedures at the same time.

If you are using Ubuntu, then the 16.04 LTS image would be the best choice:

https://www.ubuntu.com/download/server

That will not include any graphics, if it is set up correctly.

Thanks Sir.
I've downloaded that but can you please advise to problem below, in Virtual Box?

Maybe someone else will chime in regarding VirtualBox and Windows. I don't use or condone use of Windows in any way so I wouldn't be able to advise for your current situation. I usually advise running GNU/Linux on the hardware itself and then run legacy systems like Windows in a virtual machine. That give priority to learning an easier more powerful system while sandboxing the unstable, crashy one a bit: you can make snapshots of the Windows sytems and roll back to the snapshots when things go south.