Cannot access Admin sections in Magento2

[cernatcristi]

I am new to Magento and I have just installed version 2.0.4.

The install process has completed without errors but I simply cannot access any of the admin sections. I see only dashboard !

All admin sections the main menu such as PRODUCTS or STORES have link
http://mydomain.com/install_folder/admin_cjvmqn/admin/dashboard/index/key/8e15e22b718.........6ef/

Also I have tried to create a new user in the public section of the site hoping that this will enable at least the CUSTOMERS option in main menu. Nothing happened.

Please help me with some advice.
What should I do ?!

[Dmitry_Fedyuk]

How to fix the problem of loading css and javascript files? https://mage2.pro/t/259 

[ankitshah7691]

same problem....

[DevXeni]

a problem with backend (adminhtml) js! All pages, excluded dashboard. Magento 2.1, latest release, installed via CLI and composer, in developer mode