Hi guys, All the hatch patterns are missing from the hatch library. How can I recover them? Below are snap shots of the Hatch and Gradient pop-up window after running the command "Hatch".   Hope this is enough information.Thanks in advance. 

Hey Brother,
If your PAT file is not in the default hatch pattern location, check the Support File Search Paths in Options to make sure the path to your PAT file is there.

Hi thanks for your quick response. I have checked the default file location and still find that the "acad.pat" is still present. I am confused as to why the autocad program acted this way.

ya sometimes the .pat files are blocking itself. please try Unblock the PAT file by right-clicking it in Windows, choose Properties, click "Unblock" and then click OK.

How would AutoCAD hatch patterns block themselves?  It's not like they woke up this morning and decided "Hey, let's block ourselves just to give the CAD tech a headache."  Any "blocking" would have had to be dilberate on the part of the user.  I don't know of any user that would do that on purpose or even why they would do it.  
Ejas:Given that the message is "Error in hatch pattern" it leads me to believe that someone tried editing the acad.pat file.  Was that you?  Note that AutoCAD did not say "Unknown command" or "File not found."Tell us, if you type the following at the command line what does AutoCAD return as a response?Type it exactly as follows.  Exactly.(findfile"acad.pat")  Then press the Enter key.John Connor2015-03-31 12:06:46

Hey JO i am sorry, Actually I find this solution from my Friend which he find from this site  http://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/Custom-hatch-patterns-not-available-in-AutoCAD-based-products.html. 

I could not access that link.

Try the link again without the trailing  full stop (period)

Hi,John I ran the command you advised and this was the result: Command: (findfile"acad.pat")"C:\\Users\\conrad\\appdata\\roaming\\autodesk\\autocad 2013 - english\\r19.0\\enu\\support\\acad.pat"the same location previously mentioned. I did not change anything regards to the hatch patterns as I have changed workstations from before. Perhaps the person using the computer prior to me may have made changes.  
Ejas2015-03-31 23:21:07

At least it verified that you had the right file.Did you ask this other CAD person what they may have done?If you are still having a problem then run a REPAIR of the installation.  Note that a REPAIR is NOT the same as an Uninstall / Reinstall.  There is no need at this time to get that radical.