why doesn't it work-it destroyed the visibility of my site

i tried to use the polylang plug-in, which uploaded & installed easily enough. then it translated a few headers…but, knocked out my whole site with this message:

Fatal error: PLL_Model::_languages_list(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition “PLL_Language” of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition in /home/content/p3pnexwpnas06_data01/67/2394867/html/wp-content/plugins/polylang/include/model.php on line 199

thank goodness i was able to get back in through wp-admin,(go daddy hosts, which is where i usually go, but couldn’t get in at all!), & deactivate & delete polylang.
i have friends all over the world & would love something like this, but polylang doesn’t work on my wp site.
any ideas?

https://wordpress.org/plugins/polylang/