Hi Molodets,
Thanks for your note. Is it possible that you are using the github repo for The Events Calendar, and thus using our latest development code? The latest code (which is still in progress) includes a change in the Find Events string which would cause this issue. If you are using the normal 3.9.1 release, it should work perfectly.
The solution to this issue is to do a new French translation of The Events Calendar and Events Calendar PRO using a new .pot file made with the latest 3.10 code. If you’re willing to do that, please let me know and I can send you the files you need. Otherwise you’ll need to wait for someone else to update the French translation after 3.10 is released.
Thank you,
Leah