Big worries, plugin blocking after update 2.6.2

Today I updated to version 2.6.2 and after that it was impossible to open the Event menu in my backend. Unable to create or modify an event. I was asked to activate! Fortunately, the frontend calendar still worked. For the past two years everything has been working well and I have been working hard to personalize the look. Today, after hours of stress, I was able to recover the automatic backup stored on my server (thanks Plesk!) returning to version 2.5.44. I do not recommend this plugin, because the creators do not act correctly, they let us establish a whole activity, I have more than 200 events installed, and one day everything changes, without notice, the plugin stops working. I’m going to look for another plugin, hoping to be able to transfer my events.