Converting metadata to XLST format using Python causes ArcGIS Desktop to crash or fails with an error

Description

Attempting to convert metadata to XLST format using Python causes ArcGIS Desktop to crash or fails with the following error:

Error: 
000582: Error occurred during execution

Cause

The following are two causes for the conversion to fail:

Scenario 1: Python script crashes unexpectedly

The script is executed in a 64-bit environment or 64-bit background geoprocessing is turned on. This is an expected behavior. Conversion tools in the Metadata toolset are not supported in the 64-bit processing environment.

Scenario 2: Error 000582: Error occurred during execution

Conversion tools are based on C# programming language, and do not run natively in Python. Therefore, a Python script must have the required DLL files to be able to understand the calling of the desired tools.

Solution or Workaround

import arcpy
import os, sys, string

#Show 32bit or 64bit Python/Geoprocessing
import ctypes
print "4 == 32bit, 8 == 64bit"
print ctypes.sizeof(ctypes.c_voidp)

1. Open Windows Explorer.
2. Navigate to C:\Program Files\ArcGIS\Desktop10.X\Bin
3. Copy the following DLL files:
   • GpMetadataFunctions.dll
   • MetadataTranslator.dll.
4. Navigate to C:\WINDOWS\assembly
5. Paste the two DLL files into the folder.
6. Restart the machine and run the script.

Note:
The folder, C:\WINDOWS\assembly is known as the Global Assembly Cache (GAC).