Timthumb isn’t displaying any images. “A TimThumb error has occured

I had this problem when I moved a wordpress site to CloudWays which used varnish. I had to find the varnish configuration section and specifically exclude the timthumb.php script from varnish. This solved my issue because each call to timthumb.php to resize an image must be processed and it cannot be cached. I hope this helps you… I realize this question is old.