Error 500

Hi!
Thank for your great plugin!
From a few days i have an error 500 when i generate an invoice.

In my woocommerce log:

[13-Sep-2018 10:46:23 UTC] PHP Fatal error: Uncaught MpdfException: IMAGE Error (https://ret.calinou.co.il/wp-content/uploads/2018/05/684091_MRX-étoiles-multico.jpg): Error parsing image file – image type not recognised, and not supported by GD imagecreate in /home/calinoucdm/retailer/wp-content/plugins/woocommerce-pdf-invoices/vendor/mpdf/mpdf/mpdf.php:11750
Stack trace:
#0 /home/calinoucdm/retailer/wp-content/plugins/woocommerce-pdf-invoices/vendor/mpdf/mpdf/mpdf.php(12635): mPDF->_imageError(‘https://ret.cal…’, true, ‘Error parsing i…’)
#1 /home/calinoucdm/retailer/wp-content/plugins/woocommerce-pdf-invoices/vendor/mpdf/mpdf/Tag.php(3271): mPDF->_getImage(‘https://ret.cal…’, true, true, ‘https://ret.cal…’, false)
#2 /home/calinoucdm/retailer/wp-content/plugins/woocommerce-pdf-invoices/vendor/mpdf/mpdf/mpdf.php(16540): Tag->OpenTag(‘IMG’, Array, Array, 157)
#3 /home/calinoucdm/retailer/wp-content/plugins/woocommerce-pdf-invoices/includes/abstracts/abstract-document.php(193): mPDF->WriteHTML(‘ <div class=”ti…’)
#4 /home/calinoucdm/retailer/ in /home/calinoucdm/retailer/wp-content/plugins/woocommerce-pdf-invoices/vendor/mpdf/mpdf/mpdf.php on line 11750

Can you help me!!

Thanks a lot!!