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[Solved] Php8 upgrade causes a conflict with the Woocommerce PDF voucher plugin

5 Posts
3 Users
2 Reactions
Posts: 6
Topic starter
Active Member
Joined: 3 years ago

Our hosting service is retiring php7.4 in January so a resolution is quite urgent.

After upgrading to php8, the wpforo plugin causes the woocomerce PDF voucher plugin to break. I have disabled wpforo and it works fine. When I revert back to php7.4 both plugins work as expected. This is the error:

2022-11-21T21:04:21+00:00 CRITICAL Uncaught TypeError: property_exists(): Argument #1 ($object_or_class) must be of type object|string, null given in .../wp-content/plugins/wpforo/includes/functions.php:2911 Stack trace: #0 .../wp-content/plugins/wpforo/includes/functions.php(2911): property_exists(NULL, 'components') #1 .../wp-content/plugins/wpforo/includes/functions-template.php(106): wpforo_setting('components', 'page_title') #2 .../wp-includes/class-wp-hook.php(308): wpforo_hide_title('An awesome title', 134120) #3 .../wp-includes/plugin.php(205): WP_Hook->apply_filters('An awesome title', Array) #4 .../wp-includes/post-template.php(173): apply_filters('the_title', 'An awesome title', 134120) #5 .../wp-content/plugins/woocommerce-pdf-product-vouchers/includes/customizer/class-wc-pdf-product-vouchers-customizer.php(638): get_the_title(Object(WP_Post))


### WordPress Environment ###

WordPress address (URL): —
Site address (URL): —
WC Version: 7.1.0
REST API Version: ✔ 7.1.0
WC Blocks Version: ✔ 8.7.5
Action Scheduler Version: ✔ 3.5.2
Log Directory Writable: ✔
WP Version: 6.1.1
WP Multisite: –
WP Memory Limit: 512 MB
WP Debug Mode: –
WP Cron: ✔
Language: en_US
External object cache: –

### Server Environment ###

Server Info: nginx/1.21.3
PHP Version: 7.4.33
PHP Post Max Size: 128 MB
PHP Time Limit: 300
PHP Max Input Vars: 10000
cURL Version: 7.68.0

SUHOSIN Installed: –
MySQL Version: 5.5.5-10.3.34-MariaDB-0ubuntu0.20.04.1
Max Upload Size: 128 MB
Default Timezone is UTC: ✔
fsockopen/cURL: ✔
SoapClient: ✔
DOMDocument: ✔
GZip: ✔
Multibyte String: ✔
Remote Post: ✔
Remote Get: ✔

### Database ###

WC Database Version: 7.1.0

### Security ###

Secure connection (HTTPS): ✔
Hide errors from visitors: ✔

### Active Plugins (48) ###

WooCommerce PDF Product Vouchers: by SkyVerge – 3.8.0
wpForo: by gVectors Team – 2.1.1

4 Replies
Posts: 3650
Famed Member
Joined: 3 years ago

Hi @diyafury,

The problem was that wpForo conflicted with WooCommerce PDF product vouchers. 

The Problem has been fixed and would be available in the new version of wpForo.

If you need to fix it now, we can do it in your website, just need to send Admin Access Credentials to info[at] 

1 Reply
Joined: 3 years ago

Active Member
Posts: 6

@chris That's great, thank you for such a speedy resolution! We have until January before we need to upgrade to Php8, if you will be rolling out an update before then, then we're happy to hang on and stick with php7.4 until then.

Posts: 4
Active Member
Joined: 1 year ago

Hi @chris, i have a similar problem, but without Woocommerce PDF Voucher Plugin. If i enable PHP 8 it will produce critical error. Can you update this when the Update for the plugin will be roll out? Or can you fix it directly in our page ?

1 Reply
Joined: 3 years ago

Famed Member
Posts: 3650


Answered here: