Lakjin on "[Plugin: W3 Total Cache] Warning: array_shift() expects parameter 1 to be array"

Hi,

For some reason, the following message shows up arbitrarily on my website:

Warning: array_shift() expects parameter 1 to be array, null given in /home/xxx/public_html/wp-content/plugins/w3-total-cache/lib/W3/Plugin/TotalCache.php on line 789

Any idea what is up?

Thanks!

https://wordpress.org/plugins/w3-total-cache/