The error is talking about your PHP error logs. Depending on your installation, the path can vary.
/{XAMPP_INSTALLTION_FOLDER}/php/log/error.log
What ever it says in that error log, you have to fix it. Personally, I wouldn’t use XAMPP simply because I know how to install my own PHP environment. So I wouldn’t use XAMPP simply because XAMPP takes time to get new releases with current versions of PHP out and I can just install the new releases of PHP myself. Don’t need a 1-line submit update because I rather install it myself since I will know what changes and what doesn’t. “1-button click” solution or “1-line update” solution are for the ones who are lazy IMO.