[Решено] Can not translate pages anymore

Background of the issue:
I am trying to translate pages on my site скрытая ссылка using WPML, but I am unable to do so.

Symptoms:
Suddenly I can not translate pages anymore. It tried three times, failed and redirected me to WPML support.

Questions:
Why am I unable to translate pages on my site?
What could cause the translation process to fail and redirect me to WPML support?