Issue:

Causes:

• The PAT files have syntax or formatting issues.
• The pattern definitions were not properly added to the default AutoCAD PAT file.
• The directory path where the PAT files are stored is locked or not recognized as a support path by AutoCAD.
• The directory path where the PAT files are stored is a cloud drive or service.

Solution:

Test different PAT files:

Find other hatch pattern files, preferably from a different source, and try them with AutoCAD to verify functionality in the program.

Check pattern definitions:

Be sure that the name of the pattern defined within the PAT file is the same name as the PAT file. For example, if the name of the PAT file is StoneHatch.pat the first line of the file should read *StoneHatch, (the command needs to be included).

Unblock the PAT files:

1. Right-click on the hatch file and choose Properties.
2. Click 'Unblock' and then OK.

Make sure to use correct paths for the PAT files:

Custom PAT files can be put in the default location for hatch pattern files or they can be stored in an alternative location. The path for the alternative location must be added to AutoCAD in Options > Files > Support File Search Path. For MacOS, the path is added in Preferences > Application > Support File Search Path.

Check the formatting of the PAT files:

If customizing either the default acad.pat (imperial) or acadiso.pat (metric) file directly, either change the units of the drawing to match the PAT file's units or edit both PAT files so all the patterns will be seen no matter what units are in a drawing.