PHP Warning: filesize(): stat failed […] on line 159

W3 Total Cache has been working well for us but we have noticed this recurring error. I couldn’t find anyone discussing the error here or on Google search but I did find a lot of other sites indexed by Google using the search keywords: “w3” “stat failed” and “line 159.”

We sometimes receive these errors three or more times a minute, at least once an hour. Here’s a sample:

[03-Mar-2023 08:31:05 UTC] PHP Warning: filesize(): stat failed for /.../.../wp-content/cache/object/7d5/56e/7d556eb8613f033b9cd25e6957dc882a.php in /.../.../wp-content/plugins/w3-total-cache/Cache_File.php on line 159
[03-Mar-2023 08:31:05 UTC] PHP Warning: filesize(): stat failed for /.../.../wp-content/cache/object/7d5/56e/7d556eb8613f033b9cd25e6957dc882a.php in /.../.../wp-content/plugins/w3-total-cache/Cache_File.php on line 159
[03-Mar-2023 08:31:05 UTC] PHP Warning: filesize(): stat failed for /.../.../wp-content/cache/object/7d5/56e/7d556eb8613f033b9cd25e6957dc882a.php in /.../.../wp-content/plugins/w3-total-cache/Cache_File.php on line 159
[03-Mar-2023 11:47:14 UTC] PHP Warning: filesize(): stat failed for /.../.../wp-content/cache/object/421/172/42117222ef0a1c4fc4a3fd398bce8cdd.php in /.../.../wp-content/plugins/w3-total-cache/Cache_File.php on line 159
[03-Mar-2023 14:24:27 UTC] PHP Warning: filesize(): stat failed for /.../.../wp-content/cache/object/384/410/384410019b3368597cb10e34099aa564.php in /.../.../wp-content/plugins/w3-total-cache/Cache_File.php on line 159
[03-Mar-2023 16:38:12 UTC] PHP Warning: filesize(): stat failed for /.../.../wp-content/cache/object/6b9/245/6b9245cba097318e3e1070ec7b771831.php in /.../.../wp-content/plugins/w3-total-cache/Cache_File.php on line 159
[03-Mar-2023 16:38:12 UTC] PHP Warning: filesize(): stat failed for /.../.../wp-content/cache/object/3a6/a05/3a6a05ce34f8f624d5f3a8db935dec64.php in /.../.../wp-content/plugins/w3-total-cache/Cache_File.php on line 159

Please let us know if this indicates some problem in our configuration, or perhaps even, an issue with another plugin — and thank you!

WP Version: 6.1.1
PHP Version: 7.4.33
Database Version: 5.7.41
W3 Total Cache Version: 2.3.0

Thank you for reaching out and I am happy to help!
Just to confirm, you are using Object Caching and caching do disk? It’s not recommended to use Object Caching when the only available caching method is Disk. I would recommend installing php Redis or php memcached extensions if you are planning to use Object Caching. The reason for this is a potentially large number of OC files that may be cached to disk and some servers have problems dealing with those.

Thanks!