macOS Catalina Disaster and how to recover

I upgraded to Catalina last week. I have three major issues with the new version.
  1. Screenshots app doesn't work
  2. Dock is gone
  3. Slack notifications don't work
Screenshots app doesn't work


I ruled down the screenshot issue is due to new permission scheme. But I couldn't find a fix. But I found a workaround. I use screenshots to share with Slack usually, but it might not work for you.

Press CMD+Space
Click on "Option" and select Clipboard. Next time when you want a screenshot use usual shortcuts CMD+Shift+3 or CMD+Shift+4 and paste on Slack chatbox or Word document.

Dock is gone

There are two solutions to this problem. First is running below command in the shell.

defaults delete com.apple.dock; killall Dock

or

CMD+Option+D

Notifications don't work

Open "System Preferences". Click on "Notifications". Select the application you want notifications from. Click "Allow Notifications from <Application Name>"