[FIXED] How fix error "Incorrect magic number" on wordpress generate voucher PDF?

Issue

platform: wordpress + woocommerce + PDF Product Vouchers

When generating a voucher, an error sometimes pops up: could not generate voucher pdf: cannot create voucher: incorrect magic number (0)

What could be the problem?

Solution

The problem was caused by the plugin: mail log. After disabling, everything works without errors. Probably the problem is in the incorrect function of sending letters.

Answered By - Дмитрий Самохин

Answer Checked By - Cary Denson (PHPFixing Admin)