Raam Dev

@vijayabalaji5 Thank you very much for the 5-star review! I’m so happy you’re enjoying the plugin. 🙂

@prolet It sounds like you have Comet Cache 404 Request Caching enabled (Comet Cache → Plugin Options → 404 Requests) and Comet Cache is having trouble creating the symlink to the 404 error page cache file. You can either consult with your web hosting company to allow Comet Cache to create symlinks in the cache directory, or you can disable 404 Request Caching in Comet Cache.

In either case, there’s nothing malicious about the error or the problem, so it’s nothing to panic about.

@prompos123 The only workaround is to tell Comet Cache that it’s okay to cache WordPress Nonces. The way that’s done, and the disadvantages and risks associated with doing so, is explained in this article: https://cometcache.com/kb-article/what-are-wordpress-nonces-and-why-are-they-not-cache-compatible/

@massimod Have you reproduced this in a clean WordPress installation? If not, then you might have another plugin that is introducing a conflict.

The error is referring to a failure at /home/wp-includes/link-template.php on line 453, which is a call to get_year_permastruct() (a WordPress Core function). In this case, the error says that the error is a “Call to a member function get_year_permastruct() on null”… what’s null? According to the error, $wp_rewrite, which was just defined as global earlier in that function, is null, which doesn’t make sense.

So, the first place I’d start is with trying to reproduce this error in a clean WordPress installation, because it sounds like something (perhaps another plugin or some other custom code) is messing with the WordPress globals and/or changing the $wp_rewrite global in some unexpected way.

@doume In that case, I suggest following the debugging steps I mentioned in this article above: https://cometcache.com/kb-article/debugging-auto-clear-routines/

Or you can disable all of your other WordPress plugins and re-enable them one-by-one until you find the plugin that’s triggering the daily clear/wipe of the entire cache.

@doume It sounds like you might have the Cache Expiration time set to 1 day. If you don’t want the cache to expire every day, you can increase the expiration time in Comet Cache → Plugin Options → Cache Expiration Time.

@emellina If you’re only seeing that message occasionally and Comet Cache appears to be working fine otherwise, then I wouldn’t worry about it. (However, you shouldn’t be showing those warnings on the front-end of your site… see further below for a suggestion.)

That’s a PHP Warning and not actually a PHP Error and that particular warning is usually the result of a temporary issue related to the web server being unable to perform a particular action on the filesystem. The previous line in the source code checks if the cache directory exists and if it doesn’t exist it tries to create it. For some reason, the filesystem says the directory doesn’t exist, but then when Comet Cache tries to create the directory it says the directory already exists. It doesn’t make sense. 🙂

I noticed that you’re using an NFS-based filesystem. It’s likely there’s something going on at the filesystem level that is causing this behavior. But again, if you only see it occasionally, I recommend ignoring it. Otherwise, you can work with your web hosting company to see why this might be happening. (You can point them to the source code I linked to above.)

Regarding the warning being displayed on the front-end of the site: For all live production sites, it’s always recommended that you hide warnings and errors from the front-end of the site and instead log them to a log file. This is a good security practice and it also helps prevent visitors from seeing unwanted messages on the site.

You can read more about how to set WP_DEBUG_DISPLAY to false and set WP_DEBUG_LOG to true here:
https://codex.ww.wp.xz.cn/Debugging_in_WordPress