dieudonne
I have tested the News2 theme in the Today and see that the theme still work fine with the WP 5.0+
You can update the WordPress version now. However, you should create a back-up folder before update via ftp or use a backup plugin.
Note: Maybe, conflict between the plugins that you are installed.
If you have any issue, you can let me know, we will help you resolve it.
Regards,