UBB.threads PHP Forum Software Community Forums UBB.threads 7 Installation and Upgrade Support Upgrading to 7.7.5: Error:

Upgraded php from 5.4 to 7.4.16
Started getting these messages:
Deprecated: __autoload() is deprecated, use spl_autoload_register() instead in /home/wsmith/html/board/libs/phpmailer/PHPMailerAutoload.php on line 45

So decided to upgrade UBB from 7.6.1.1 to 7.7.5
During the upgrad, after the screen:
Config file update

The next screen shows:
/home/wsmith/html/board/styles/ubbthreads_1617365481.css.php is not writeable. Please fix permissions and refresh this page.
But there's no such file.

Help!