I'm Ivan from toolset development team. For now I can only confirm that this is the real issue caused by select2 library update. We are already working on this and we will publish hotfix for this soon as possible.
Sorry for the delay, hotfix for this issue is available now. You should able to update Layouts to version 1.8.6 from wp-admin and update will solve this problem.
Thank you,
Ivan
This ticket is now closed. If you're a WPML client and need related help, please open a new support ticket.