The latest update was disastrous - Nothing works

I just updated to the last version and now I cannot log in from the front end. When I click the Login Form I get "Javascript:void(0);" (see https://kfirluzzatto.com/my-blog). I worked fine before I updated, so I assume this is an issue with the new version.

I tried to create a post in the back end, but when I tried to save it or preview it, it was not saved and simply disappeared. At this time I cannot create any new posts, so your quick attention would be appreciated.

Update:
The whole web site went down after I tried again to write a post, and trying to view it now gives the following notice: Parse error: syntax error, unexpected '{' in /home4/kfir/public_html/kfirluzzatto.com/plugins/user/easyblogusers/easyblogusers.php on line 439

I'll need to try to restore it from backup.