Wordpress 4.6 update caused WHMCS integration failure - line 376

Just updated WordPress to version 4.6 and I am now getting the following integration error with WHMCS Wordpress Integration 1.4.4

Warning: file_get_contents(/home/xxxxx/public_html/wp-content/plugins/whmcs-wordpress-integration/cache/e64dac59086b730bdf42e33aa5cd6bc6.txt): failed to open stream: No such file or directory in /home/xxxxx/public_html/wp-content/plugins/whmcs-wordpress-integration/includes/class-whmcs-wordpress-integration.php on line 376

Any ideas as to what may be causing this? The fact its a cache problem makes me think its directory permissions but I'm just guessing to be honest. Any solutions or even a temp fix appreciated at the moment. :slight_smile: