Some users are having issues with Polylang 1.2.x as for example it breaks the Avada theme. Since the database has been modified between 1.1.6 and 1.2, it is not as easy as usual to revert to the previous version.
For people who have not made a database backup before the upgrade and who need to revert to 1.1.6, a plugin is available on pastebin: http://pastebin.com/0TdQzQLv
Please follow carefully the instructions and do not orget the database backup.
You can ask questions on this procedure on this thread. Please open a separate thread for Polylang 1.2.x bug reports.