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Images in PDF displays as a red cross (https / mpdf)
First please make sure, that you are not on a localhost AND do not have any .htaccess / .passwd on your sever. Because our plugin uses HTTP to get the images for the PDF creation and if your server blocks the images from public it won’t work.
Problem not solves? Read further:
Please make sure you have installed / configured the following in your Server PHP Extensions:
- CURL Enabled (php_curl.dll enabled)
- PHP.ini (allow_url_fopen = On)
- GD Library installed
To debug image loading go to plugin settings > advanced settings. There enable the MPDF Debug mode:
Look what the image errors show. Maybe you find the issue yourself.
If images still do not display you can solve the issue by the following ways:
Quick and Dirty:
Add the following to the mpdf.php file on line 12954 -> function: file_get_contents_by_curl()
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
Source: https://stackoverflow.com/questions/5657382/curl-php-restful-service-always-returning-false
Better:
The better solution is to manually add only the certificate(s) or CA(s) you want to accept
;;;;;;;;;;;;;;;;;;;; ; php.ini Options ; ;;;;;;;;;;;;;;;;;;;; curl.cainfo = "C:\xampp\php\extras\ssl\cacert.pem"
Source: https://stackoverflow.com/questions/24611640/curl-60-ssl-certificate-unable-to-get-local-issuer-certificate
On Nginx?
Some nginx server disallow some agents in the CURL header. Therefore you will need to change the header. Go to plugin-folder/includes/mpdf/mpdf.php > Line: 12965.
Then change the CURLOPT_USERAGENT value to ‘User-Agent: curl/7.39.0’
Example:
curl_setopt($ch, CURLOPT_USERAGENT, 'User-Agent: curl/7.39.0');
We resolved it. Your help article would be greatly improved if you suggest the following:
$this->mpdf->showImageErrors = true;
$this->mpdf->debug = true;
Add that to link 279 build_pdf() in class-woocommerce-pdf-catalog-public.php
once that was added the PHP debug log showed:
Jan 03 08:33:26 ip-10-0-36-166 debug: [03-Jan-2018 16:33:22 UTC] PHP Fatal error: Uncaught MpdfException: IMAGE Error (https://XXX/file.png): Could not find image file in /var/www/wordpress/htdocs/wp-content/woocommerce-pdf-catalog/includes/mpdf/mpdf.php:11752
this showed us the error was related to a DNS issue locally:
curl https://XXX/file.png
curl: (6) Could not resolve host: example.com
Once we saw that error, the problem was obvious
Thanks for the assistance –
Rod
Thank you for the valid feedback. We updated our FAQ 🙂