py2exe MemoryLoadLibrary failed loading _ssl.pyd, Win7<->Win10

Introduction

I have a script which uses SSL and is build with py2exe (bundle_files=1, pack everything together into the *.exe)

Now I faced this problem

Running py2exe on Win7 creates an *.exe which will run in Win7 and Win10
Running py2exe on Win10 creates an *.exe which will run in Win10 but produces this error in Win7:

ImportError: MemoryLoadLibrary failed loading _ssl.pyd 

Workaround

Setting bundle_files to 3 (don't pack) will result in an *.exe which is working fine in Win7 even when it is built on Win10.

I tried out some py2exe options and suddenly it worked, when changing bundle_files. But I don't understand why.

My setup

• python 32bit 2.7.11
• ssl.OPENSSL_VERSION => 'OpenSSL 1.0.2d 9 Jul 2015'
• py2exe 0.6.9

Same on both machines (win7 and win10).

This is a minimal demo to reproduce it:

demo.py

import ssl print "import done" 

It can be built using this
exebuilder.py

from distutils.core import setup import py2exe import sys sys.argv.append("py2exe") # run py2exe (instead of supplying the command line argument) # exclude some DLLs dll_excludes = [ # win9x leftovers "w9xpopen.exe", # don't import these - otherwise win7 created *.exe won't work in winXP # http://stackoverflow.com/questions/1979486/py2exe-win32api-pyc-importerror-dll-load-failed "mswsock.dll", "powrprof.dll" ] sys.argv.append("--dll-excludes=%s" % ",".join(dll_excludes)) app_name = "win10ssl" params = { 'zipfile': None, # pack everything into the *.exe 'options': { "py2exe": { "compressed": 1, "optimize": 2, # bundle_files # 1 = EVERYTHING packed into the *.exe # 2 = everything except for the pythonXX.dll # 3 = don't pack "bundle_files": 3 } }, 'version': "0.0.1.0", 'description': "demo to show MemoryLoadLibrary error", 'name': app_name, 'console': [{ "script": "demo.py", "dest_base": app_name } ] } setup(**params)