Error: ImportError: DLL load failed: %1 is not a valid Win32 application

Error Message

When attempting to import ArcPy into ArcGIS Pro, the import statement returns the following error message:

Error:   
ImportError: DLL load failed: %1 is not a valid Win32 application.

 

Cause

ArcGIS Pro's 64-bit Python interpreter is attempting to import a 32-bit module, as the Environment Variable 'PYTHON' or 'PYTHONPATH' is referencing a folder containing ArcMap's 32-bit ArcPy module.

Solution or Workaround

1. Run the following script in the Python interpreter in ArcGIS Pro:

   import sys
   for path in sys.path:
   	print (path)

    

   Note:
   The script loops through each path the Python interpreter references for modules. If the generated lists include the ArcMap's 32-bit ArcPy module, move to step 2. 
   

    
2. Navigate to Control Panel > System > Advanced system settings > Environment Variables. The Environment Variables 'PYTHON' or 'PYTHONPATH' is defined here.
   
   
    
3. Edit the 'PYTHON' or 'PYTHONPATH' variable and remove all references to the ArcMap 32-bit installation of Python.
4. Restart the machine.

Related Information

• Esri Canada: Configure your Python IDE to work with ArcMap and ArcGIS Pro's ArcPy
• Problem: Unable to import arcpy
• FAQ: Why do Python scripts fail on a machine with both ArcGIS for Server and Desktop installed?