Suddenly I get ‘Something went wrong’ error

If you are using version 2.6.* it has stopped working due to the stop of support for this version in our API servers. We stopped supporting it for security reasons, as this version was released 3 years ago.
To keep your website secure, you need to update your plugin to the latest version.
To do this, you need to disable the plugin in the 2FAS dashboard, or from the database level if you do not have access: In the wp_options table locate in the option_name column locate twofas_is_plugin_enabled key and change value from 1 to 0.
Next update your plugin in plugin directory, and enable plugin again.