Timthumb Permission Errors

Hi,

After updating CRP to the latest version, I am getting a lot of PHP errors related to timthumb, even after I have disabled it from the panel. I have given thimtub.php chmod 755 access but this did not solve the issue. Any idea how I can resolve this error ?

stderr: PHP message: PHP Warning: touch(): Unable to create file ./cache/timthumb_cacheLastCleanTime.touch because Permission denied in /var/www/wp-content/plugins/contextual-related-posts/timthumb/timthumb.php on line 476

line 476 is : if (!touch($lastCleanFile)) {
$this->error(“Could not create cache clean timestamp file.”);

https://wordpress.org/plugins/contextual-related-posts/