Error 500 since update to 1.4.4

At first, it was complaining that wp-integration.php was missing from the WHMCS site. This was pulled from the package and placed but the 500 error persists. This missing file error for wp-integration.php was resolved but now I'm getting errors indicating that it cannot read from a cache folder. How do I resolve this?

PHP Warning: file_get_contents(/home/creative/public_html/wp-content/plugins/whmcs-wordpress-integration/cache/2483da8dd2196a5daef0f97f15699816.txt): failed to open stream: No such file or directory in /home/creative/public_html/wp-content/plugins/whmcs-wordpress-integration/includes/class-whmcs-wordpress-integration.php on line 376