Hi Nicole,

If you added hatch patterns from Hatch Library palette (using "add hatch"), than you need to cleanup all symbolic links to the hatch patterns from the "Users/YOUR_USER_NAME/Library/Application Support/Autodesk/roaming/AutoCAD LT 2015 Standalone/R20.0/enu/Support/" folder.
The icons of the Symbolic links looks like ordinary files, but have small arrow at the bottom.

Maxim