Go to Employees > Assignments, and select a job assignment for each employee.
Edit the text file “SettingsOverride.txt” located in the Data Root Folder.
To find the data root folder, go to Navigation > Setup > Program Options > General, and look in "Data Root Directory".
You will find 2 settings that are commented
;AssignHomeDept=No
And
;AssignDefaultJob=No
For each of these, remove the comment mark and set the value to Yes
AssignHomeDept=Yes
AssignDefaultJob=Yes
For differential, you need to also ensure that the employee has Differential Enabled (General tab of Employee Detail screen).
The changes should be retroactive