[StorageFan]

Little scheme
Kodi 18 >> works only with python 2
Kodi 19 >> works only with python 3

if you have installed both python enviroments
you have to manage the packages in both enviroments, depends what you need

Well, I started with KOD 19 first, but when it failed, I installed KODI 18 in parallel, because I was able to successfully install your Netflix plugin on my Sony TV under KODI 18. So I thought, I'd better stick with what works.
That's why both KODIs are installed on my QNAP now.

Same with Python. Since a friend asked me, if I had Pythong 2.7 installed, I installed it through the QNAP App Center parallel to Python 3.
 

i think you should install the pip for python 3 only
sudo apt-get install python3-pip

then install pycryptodomex to python 3:
pip3 install pycryptodomex

or if not works again (before uninstall the package) you can try:
pip3 install --user pycryptodomex

i do not know if these info can help you

Welll, thank you very much for at least trying. I highly appreciate it.
I tried your commands and this is what the CLI responded:



Looks to me as if it doesn't make any difference, if I use the command
pip3 install --user pycryptodomex
pip install --user pycryptodomex
or
python3 -m pip install --user pycryptodomex

All three commands consider the library to have been properly installed.
 

perhaps it is possible avoid install another package (python3-pip) and use these commands (not tested but you can try):

python3 -m pip install package
python -m pip install package

Both work as well, but produce the same results as a direct pip command (see above).

I also tried to start KODI 19 instead since you said that it uses Python3, but it produces the same Netflix plugin error as KODI 18.

Here is the Logfile for KODI 19:
https://paste.kodi.tv/safecipoto

And while it says first:
2020-09-04 12:55:17.041 T:31811 NOTICE: CAddonMgr::FindAddons: script.module.pycryptodome v3.4.3 installed
2020-09-04 12:55:17.611 T:31882 DEBUG: CPythonInvoker(0, /opt/Kodi19L/.kodi/addons/plugin.video.netflix/service.py): setting the Python path to /opt/Kodi19L/.kodi/addons/plugin.video.netflix:/opt/Kodi19L/.kodi/addons/script.module.addon.signals/lib:/opt/Kodi19L/.kodi/addons/script.module.certifi/lib:/opt/Kodi19L/.kodi/addons/script.module.chardet/lib:/opt/Kodi19L/.kodi/addons/script.module.future/libs:/opt/Kodi19L/.kodi/addons/script.module.idna/lib:/opt/Kodi19L/.kodi/addons/script.module.inputstreamhelper/lib:/opt/Kodi19L/.kodi/addons/script

it later produces the exact same errors in the logfile as mentioned above in my previous post for KODI 18:
2020-09-04 12:55:25.766 T:31908 ERROR: EXCEPTION Thrown (PythonToCppException) : -->Python callback/script returned the following error<-- - NOTE: IGNORING THIS CAN LEAD TO MEMORY LEAKS! Error Type: <class 'ModuleNotFoundError'> Error Contents: No module named 'Cryptodome'
etc.


I don't know if me failing to install a package called build-essential is causing the problem or if Cryptodomex is not fully accepted by the QNAP OS as a replacement for Crytodome, but for some reason neither KODI 18 nor KODI 19 can properly use the installed pycryptodome package as it seems.

Again, any input is highly appreciated.