Hi Chouby
I have a similar problem. I installed Polylang with a Centum Theme from Purthemes, hosted by Siteground. I installed WordPress and Polylang automatically, so they should be the newest versions.
I tried to use the language button in the top bar in the dashboard, then the whole admin panel broke. Now, when I login, I directly get a blank page with this line:
Fatal error: Call to undefined method PLL_Links::get_translation_url() in /home/himala13/public_html/wp-content/plugins/polylang/include/wpml-compat.php on line 89
I deleted the whole polylang folder via cpanel/FTP, then the error was gone. I reinstalled the plugin, and it was instantly there again. The plugin worked for a couple of hours before the error showed up the first time, and I really liked it. It would be pity if I can't use it!
Any ideas?