If you get such an error on Windows:

import cefpython3
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python3\lib\site-packages\cefpython3\__init__.py", line 59, in <module>
    from . import cefpython_py36 as cefpython
ImportError: DLL load failed: The specified module could not be found.

Then most probably this is caused, because you are missing "msvcp140.dll" dependency (for Python 3 for example). This is a dependency for Python C++ extensions (eg. cefpython_py36.pyd depends on it). For Python 3 to fix this download Visual C++ Redistributable for VS2015 (13 MB) - this is just a VC++ redistributable, not a Visual Studio package. For 32-bit download "vc_redist.x86.exe" file and for 64-bit download "vc_redist.x64.exe" file.

Explanation: msvcp140.dll is the DLL for the C++ runtime library. This dependency is added by Cython when building CEF Python module. It seems that Python 3.6 only ships "vcruntime140.dll" which is the DLL for the C runtime library.

When using pyinstaller/py2exe tools for freezing application into exe then these tools should automatically detect the msvcp140.dll dependency and ship it with your application. So it's not an issue for packaged apps.

This info is also available in the Knowledge Base document.

Possible solutions

1. Ship the msvcp140.dll file along with CEF and CEF Python binaries