My computer runs Ubuntu 18.04; I use MySQL, MySQL Workbench (both 8.0.13) I too am using SHA2 for passwords rather than what had been used in MySQL 5.7.
1) Open the Base Wizard.
2) Connect to an existing database
3) Select MySQL.
4) Connect directly.
5) Enter database name and localhost as server.
6) Enter user name and check the Password required box.
7) Click "Test Connection" button.
8) Enter password for the user and click OK.
9) Error message: Can't initialize character set unknown (path: compiled_in)
*** This bug has been marked as a duplicate of bug 122560 ***