Plugin Breaks Backend

I’m sorry about that. I’m no sure what could be causing this – our plugin doesn’t load for frontend pages so that doesn’t explain why it makes your site slower and I also don’t know why it makes the backend inaccessible (no known bugs yet). By “unable to access”, do you mean it is crashing, or slowing it down like the frontend? Do you have access to the PHP error logs, and if so, is there anything in there that points to the PDF Invoice plugin that explains the issue? Are you using the free base plugin or do you also use any of the paid extensions, and if yes, which versions? Any additional information that you can provide is more than welcome.

I hope we can resolve this quickly together!

Hey Ewout,

Whenever the plugin is active the backend is inaccessible and 504’s, while the entire front-end notices a marked drop in speed.

Here is an excerpt from the slow error log file that led us to this plugin being the issue:

script_filename = /www//wp-admin/admin-ajax.php
[0x00007f86b9e99fa0] date() /www/wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-log-handler.php:28
[0x00007f86b9e99f30] format_time() /www/wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-log-handler.php:42
[0x00007f86b9e99dc0] format_entry() /www/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php:124
[0x00007f86b9e99be0] format_entry() /www/wp-content/plugins/woocommerce/includes/log-handlers/class-wc-log-handler-file.php:97
[0x00007f86b9e99ab0] handle() /www/wp-content/plugins/woocommerce/includes/class-wc-logger.php:140
[0x00007f86b9e99940] log() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/wcpdf-functions.php:197
[0x00007f86b9e99780] wcpdf_log_error() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:436
[0x00007f86b9e995c0] init_tmp() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:368
[0x00007f86b9e993e0] get_tmp_path() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:469
[0x00007f86b9e98ae0] copy_fonts() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:449
[0x00007f86b9e98920] init_tmp() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:368
[0x00007f86b9e98740] get_tmp_path() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:469
[0x00007f86b9e97e40] copy_fonts() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:449
[0x00007f86b9e97c80] init_tmp() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:368
[0x00007f86b9e97aa0] get_tmp_path() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:469
[0x00007f86b9e971a0] copy_fonts() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:449
[0x00007f86b9e96fe0] init_tmp() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:368
[0x00007f86b9e96e00] get_tmp_path() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:469
[0x00007f86b9e96500] copy_fonts() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:449
[0x00007f86b9e96340] init_tmp() /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php:368

The entire file is basically that error on repeat.

The PHP Error Log, looks similar, here is an excerpt of the infinitely repeating error there:

[26-Aug-2019 14:52:34 UTC] PHP Warning: file_put_contents(/www/wp-content/uploads/wpo_wcpdf/attachments/.htaccess): failed to open stream: Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 452
[26-Aug-2019 14:52:34 UTC] PHP Warning: touch(): Unable to create file /www/wp-content/uploads/wpo_wcpdf/attachments/index.php because Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 453
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 432
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: file_put_contents(/www/wp-content/uploads/wpo_wcpdf/attachments/.htaccess): failed to open stream: Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 452
[26-Aug-2019 14:52:34 UTC] PHP Warning: touch(): Unable to create file /www/wp-content/uploads/wpo_wcpdf/attachments/index.php because Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 453
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 432
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: file_put_contents(/www/wp-content/uploads/wpo_wcpdf/attachments/.htaccess): failed to open stream: Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 452
[26-Aug-2019 14:52:34 UTC] PHP Warning: touch(): Unable to create file /www/wp-content/uploads/wpo_wcpdf/attachments/index.php because Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 453
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 432
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: file_put_contents(/www/wp-content/uploads/wpo_wcpdf/attachments/.htaccess): failed to open stream: Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 452
[26-Aug-2019 14:52:34 UTC] PHP Warning: touch(): Unable to create file /www/wp-content/uploads/wpo_wcpdf/attachments/index.php because Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 453
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 432
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: file_put_contents(/www/wp-content/uploads/wpo_wcpdf/attachments/.htaccess): failed to open stream: Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 452
[26-Aug-2019 14:52:34 UTC] PHP Warning: touch(): Unable to create file /www/wp-content/uploads/wpo_wcpdf/attachments/index.php because Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 453
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 443
[26-Aug-2019 14:52:34 UTC] PHP Warning: mkdir(): Input/output error in /www/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php on line 432
[26-Aug-2019 14:52:34 UTC] PHP Fatal error: Allowed memory size of 314572800 bytes exhausted (tried to allocate 20480 bytes) in /www/wp-includes/capabilities.php on line 971

We initially attempted to rollback the plugin to the most recent version, as it had been updated last week, but both versions appear to cause the issue.

It may be worth noting that according to the store owner there was an increase in traffic & orders (unfortunately I don’t have any data to represent this), so my running theory is that a bunch of backed up processes is our culprit, though that is just a theory.

Thanks!

-Simon

Hello Simon,
Thanks for sharing that. I think this is a permissions issue on the temporary folder, did anything change on the server (i.e. backup restored or moving files otherwise?).
The quickest way to resolve this is to remove the temp folder /wpo_wcpdf from /www/wp-content/uploads/ entirely – this will re-initialize the creation process and hopefully thus fix the issue. If not, I recommend checking permissions globally on the wp-content/uploads folder.

I’ll look into a way to prevent this from happening in the first place, but this may take some time to release. Apologies for the inconvenience!

Hey Ewout,

Thanks for the information!

None of those changes were made as far as I’m aware, but I’m double checking with the server team to know for sure.

I took a look in the Uploads folder and was unable to find a folder called /wpo_wcpdf.

Are there any other server locations that folder may be?

Thanks!

-Simon

No that’s where it’s always been and there is no alternative location… Is the uploads folder writable? A write permissions error is what a search for the “mkdir(): Input/output error” points towards.

p.s. sorry if this wasn’t obvious, but the folder name is wpo_wcpdf without the slash.

Hey Ewout,

Thanks for the information.

That folder is definitely not present in the /uploads folder, and I’m not sure how to check on the permissions, so I’m forwarding this all over to the server team to have them take a look.

As soon as I get more information from them I’ll follow up here.

Thanks!

-Simon

Hey Ewout,

I reached out to the server team & as soon as they reset the folder permissions it began to show as expected.

We cleared that folder out, and as you predicted the site is now working properly with the plugin active.

Are you aware of a way we can prevent this error going forward, or does this appear to be a one time glitch?

Thanks so much!

-Simon

Folder permissions don’t change out of the blue and this is not something that can be done from within the plugin. I’d say this is a one time glitch, possibly to do with a backup being restored or migration made incorrectly – things that should be very seldom. I’d ask the server team what could have caused the folder permissions to change, perhaps they can tell you what happened so you know what to look out for.

Glad to hear the issue is resolved now!