Your screenshot does not say what you have done, only the packages no longer required. To find what was done look at the end of apt history log and try to reinstall them.
less /var/log/apt/history.log

Edited by oldfield at 2020-1-24 23:51

sudo apt autoremove
sudo apt install deepin-desktop-base

I can't pass the Deepin logo... stays pulsating... whatever happened, it removed dde-control-center, dde-daemon, and other important files not mentioned on the screenshot I provided. Repair function is useless and login with recovery mode to use dpkg, fsck, and grub, do not solve anything at all. If I try to drop to root shell prompt, it tells me "cannot open access to console the root account is locked. I'm screwed! Need help!

What do you mean by saying "I can't pass the Deepin logo"?

If you cannot login to the GUI, then you may try TTY: press Ctrl-Alt-F2, and try login with your username and password, then run the command above.

If you still have access to the desktop, then it means a part of DDE still works. Then repairing should be easier, as you can check the content of apt history ( /var/log/apt/history.log ) by your text editor (or just execute the command "  less /var/log/apt/history.log " in the terminal.

I would recommend doing a fresh reinstall if it broke too much when you tried to install the videocodec, if you don't want to bother too much with commands.

Can you believe TTY doesn't even work? I have a backup of all my documents, videos, music, pictures, downloads and whatever I had on my Desktop. The headache of fixing it is not worth it. Will be reinstalling Deepin 15.11. I do appreciate your help....

You can use timeshift to back up your system after reinstalling. Timeshift is awesome.When  deepin is broken, I can usblive to restore system.

Did you say you have some important files on your desktop?
If you have another computer and a removable media, maybe you could try to make a live system in order to start your computer temporarily and then backup your files.
WARNING: Making a live system is going to format your media and damage those data.
As for the Live System, you can download any of the popular Distros. If you are not so familiar with Linux, you can just make a Deepin Live System.
At last, I would recommend doing a fresh reinstall if your system is in a very bad condition.

Last of last: If you're able to log into your TTY as the comments above, it would not be required to have another Computer,
just download the live system mirror,
and then dd it into your Removable media.
If it works, just comment there and reply me, we'll help you out.

So next time you get stuck in such a scenario, you need to edit your passwd file and give your root account a password. You are getting this error because there is no password assigned to root and is disabled.

So whenever you assign one and enable it, you should be able to boot in recovery mode and terminal into the root and restore missing packages, such as in your case.