odoo11 errors related to Werkzeug and Jinja2 on Ubuntu 18.04

[ammarelamin]

I tried to install Odoo v11 on Ubuntu 18.04.3 on many laptops, for my students. The script used to work fine 3 months ago, the moment the installation completes, odoo-server service run and immediately Odoo runs on port 8069. Last week something went wrong, 4 devices, no one installed correctly, the installation finishes, but when testing localhost:8069 " default port, didn't change it in script" it shows "unable to connect", I try to start odoo manually through ./odoo-bin in odoo-server folder, an error shows up, "ModuleNotFoundError: no module named werkzeug.contrib". I searched for solutions, I found one, it was sudo pip3 uninstall werkzeug and then sudo pip3 install werkzeug==0.16.0 , after fixing this error, another error pop-up when running ./odoo-bin, and something like "some packages installed in a way PackageLoader could not understand", fixed by running sudo pip3 uninstall Jinja2 and then sudo pip3 install Jinja2==2.10.1 and then the server starts without errors and everything is fine. Am Odoo technical trainer and I use this script a lot.