Try doing a Dock restart using the following Terminal command:
Log out/in and test. If that doesn’t work, you need to look in your user Library/Applications Support/Dock for the .db. Use the Finder “Go To Folder” command. Enter ~/ Library/Applications Support/Dock. Move the .db to your desktop.
Then try a dock reset.
Applications/Utilities/Terminal enter the command
Log out/in test. If it works okay, delete the .db from the desktop.
If the Dock is the same, return the .db to where you got them from, overwriting the newer ones.
If you prefer to make your user library permanently visible, use the Terminal command found below.
You might want to bookmark the command. I have to use it after every update. I have also been informed that if you drag the user library to Finder it will remain visible.