[Решено] Languages are not populated while setting up

Background of the issue:
In order to setup WPML I need to select a default language and translation language. However, values for default and translation language are not populated in the dropdown.

Symptoms:
Languages are not populated while setting up WPML.

Questions:
Why are the default and translation language values not populated in the dropdown?
How can I populate the language dropdown to complete the WPML setup?