after language change, the admin panel or website not loading

Difficult to know where to start. Lets check you have enough memory.

Can you make a plain text file called test.php containing:

<?php
phpinfo();

and upload it using ftp or your hosts file manager software to your wordpress root directory. Run it by typing its path in your browser:
http://www.jas.lv/test.php

What does it say for the memory_limit value?

Now delete the file as it is a security risk.