Just to clarify:
On certain installations to drives other than C:, two errors appear each time a user either initializes an ACAD session, or when a user attempts to run a command.
In the first case, the following error appears:

To resolve this, simply navigate to the following location:
C:\Users\Admin\AppData\Roaming\Autodesk\AutoCAD 2021\R24.0\enu\Plotters\Plot Styles
Delete the shortcut for “Add-A-Plot Style Table Wizard.lnk
A new, correct shortcut will replace this deleted one on the next startup.
For the “Unable to find main dictionary” error,

many online solutions say to simply enter the correct path in the “Main Directory” field under “Text Editor, Dictionary, and Font File Names” category.
For alternate drive installations though, this will not allow any entries to be made, and there is a “None Available” error:

Resolution:
Search for any .dct (dictionary) file within the installation path for ACAD (support folder) and copy the path to the “Support” folder for your installation. Mine was in “D:” drive, where I had installed ACAD:
D:\Autodesk\AutoCAD 2021\Support
Copy this path.
Next, open ACAD>Options and expand the “Support File Search Path” tree in the “Files” tab.
Click the “Add” button and paste the path to the “Support” file you previously copied.

Restart ACAD and the errors should be gone.