W3TC causing fatal error on my site

@andrewsamplab In file manager or FTP try renaming /wp-content/db.php to db.php.bk it will hide the problematic file until they release an update addressing the issue. You may have to manually revert the file name back after update

Hello @neverknowsbest @andrewsamplab
Thank you for the information.
@andrewsamplab you can safely delete the db.php file as it’s the W3 Total Cache Database module. This will be created again once the DB cache is activated.
Can you please confirm that you are also on InMotion Hosting?
Please keep DB Cache and Object Cache disabled for the time being especially if on shared hosting and caching to disk.
We are working with IMH to resolve this and if you encounter an issue again please drop us a note directly via the plugin so we can inspect the system when the error is occurred.
Thanks!

Thanks and yes, I’m with IMH on shared hosting.

Hello @andrewsamplab

Thank you for the information.
Please let us know if the issue reoccurs.
Thanks!

Hi Marko,

Thanks for your reply and your support. I’m with InMotion Hosting on a shared server.

I can log in to my admin panel again after I’ve renamed the W3TC folder on the FTP server (the plugin got automatically disabled afterward).

I didn’t make any changes or updates before the issue started.

I keep my fingers crossed that you can resolve the issue (together with IMH), thanks for looking into this. I’ll re-install and activate W3TC once you give the green light.

Thanks and best regards,
Ramona

Thanks. I have deleted W3TC and everything is working fine now. I’m reluctant to re-install it until we know all the issues are resolved with IMH.

Hello, @plantydelights @andrewsamplab

We are working on resolving this. However, the problem is that we cannot detect the issue unless we check the environment that is currently having an issue. Live issue.
SO far, the problem was narrowed to DB Caching and Object Caching on Shared hosting and caching method: Disk.
As a rule of thumb, Object Cache is not worth using on shared hosting for the same reason as Database Cache, i.e. database is often not the performance bottleneck, but disk input-output operations.
However, like Database Cache, it can be beneficial to use if you are on VPS or a dedicated server, get a lot of traffic, have a lot of comments. Also, if you know that database is the bottleneck of your website performance, then Object Cache (like Database Cache) is beneficial to use. But in this case, it’s recommended to use Memcached or Redis options.
So in your case, and with the other issues you mentioned, it’s best not to use Object Cache/DB cache on a shared server.
SO you can re-install the plugin just make sure not to use the mentioned settings if on a shared server.
Thanks!

@vmarko I followed these directions when you mentioned it.
Check .htaccess File (make backup)
W3TC will create many directives in the .htaccess file to control caching behavior. Each section will start and end with comments like “#BEGIN W3TC Page Cache core” and “#END W3TC Page Cache core”.
Ensure that no residual entries are leftover in your .htaccess file after deleting the plugin.
Delete wp-content files and folders
– cache folder
– w3tc-config folder
– object-cache.php (if exists)
– advanced-cache.php (if exists)
– dbcache.php (if exists)
– upgrade folder
– delete w3-total-cache folder in wp-content/plugins/ (if exists)

And deleted the plugin from the ftp. Since I was unable login to my website. When I reinstall w3tc will it still have all my old settings? Or will I have to redo all of my settings again? I was also on Inmotion hosting shared server.

Hello @mirrorlure7m,

No, the old settings are gone so you will need to configure the settings again.
The settings are stored in the master.php file but since you were not able to log in, and now that all files are deleted, you can re-install W3 Total Cache without fear of breaking your website again. Just make sure not to enable Database cache and object cache.
Thanks!

@vmarko I prefer to wait till a fix is released and everything can be confirmed working with inmotion shared server.

@vmarko Thank you for the update and the explanation. Will re-install the plugin and make sure that DB cache and object cache are not enabled.

@vmarko

I get the message that some files seem to be missing or out of place. As I failed to reinstall W3TC (the site crashed again), I’d like to remove these files. Can you please confirm that the following 3 files are connected W3TC and that I can safely delete them?

…/wp-content/advanced-cache.php
…/wp-content/db.php
…/wp-content/object-cache.php

Thanks and best regards

Hello @plantydelights
Yes, you can safely remove those files.

…/wp-content/db.php
…/wp-content/object-cache.php

This means that you’ve had both DB Cache and Object Cache enabled so you can remove those.

Please follow the instructions below to completely remove W3 Total Cache.

1. Check .htaccess File (make backup)
W3TC will create many directives in the .htaccess file to control caching behavior. Each section will start and end with comments like “#BEGIN W3TC Page Cache core” and “#END W3TC Page Cache core”.
Ensure that no residual entries are leftover in your .htaccess file after deleting the plugin.
2. Delete wp-content files and folders
– cache folder
– w3tc-config folder
– object-cache.php (if exists)
– advanced-cache.php (if exists)
– dbcache.php (if exists)
– upgrade folder
– delete w3-total-cache folder in wp-content/plugins/ (if exists)
3. Delete Cached Files from CDN (if using CDN)
Besides deleting all the relevant files, if you use CDN then ensure to purge the cached content from your CDN. This is necessary when you enabled the minify option in W3TC settings. You should delete the minified and combined scripts and CSS files from your CDN server to avoid the site breaking on the browser.
4. Go to your wp dashboard and re-install W3 Total Cache

Thanks!

I had the exact same issue last week. I received emails that my site had a critical issue caused by the W3TC plugin.

I went through the steps listed above. I then installed W3TC again from scratch and configured it as before (as working for 1+ year).

The next day, the same thing occurred again.

At this point, I do not feel confident re-enabling the plugin unless there is fix or work-around forthcoming. I currently left the plugin folder renamed, as I cannot login if I don’t, even with the plugin de-activated. Of course I now get the ‘files appear to be missing’ messages.

Wordpress and all other plugins are up-to-date with the latest versions.

Failures occurred on 9/3/2020 and 9/5/2020 at approximately 12:30 a.m., at least that’s when the emails were sent. I think that the problem started with the last W3TC update.

My site is running on an InMotionHosting shared server, as several others here with the problem seem to be.

Hello @mikeb8s

Thank you for the information.
We are working with the IMH to resolve this. At this point, the bottleneck of the issue you are experiencing as mentioned in the other thread related to this is the DB Caching and Object Caching on shared hosting when caching to Disk.
Please make sure not to user DB caching or OC caching (Disk caching method) if on shared hosting as it’s not recommended to use this anyway if you don’t have VPS or a Dedicated server.
Thanks!