ACAD/ACA/ACAD MEP: Plot styles and converting them

If you are missing your plot styles it could be one of the following fixes that will resolve your issue.

1. It could be that the Plot dialog box's plot styles is not expanded to the right.
2. It could be that the plot styles are not pointing to the correct location from within your Options dialog box on the File tab. Expand "Printer Support File Path, then expand "Plot Style Table Search Path" and make sure you have the correct path pointing to your plot styles folder typically found in the C:\ProgramData\Autodesk\Software name and version\enu\Plotters\Plot Styles\. 
3. If your drawing is using the named plot styles which are the .std and you need the .ctb styles you would need to convert the drawing to switch to the .ctb plot styles. This is done by typing CONVERTPSTYLES at the command line and click the OK button.