» Plugin stops working when upgrading to PHP 8.1 or above

Hey there!
I updated my website to PHP 8.1 (and also tested 8.2) via IONOS and received the following error message which made the site unusable (internal server error):

Wenn du Hilfe bei diesem Problem suchst, wirst du möglicherweise nach einigen der folgenden Informationen gefragt:
WordPress-Version 6.8.1
Aktives Theme: Hello Elementor (Version 3.4.4)
Aktuelles Plugin: Import WP (Version 2.14.12)
PHP-Version 8.1.33

Fehler-Details
==============
Ein Fehler vom Typ E_ERROR wurde in der Zeile 62 der Datei /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Common/Rest/RestManager.php verursacht. Fehlermeldung: Uncaught TypeError: ImportWPCommonRestRestManager::__construct(): Argument #2 ($exporter_manager) must be of type ImportWPCommonExporterExporterManager, ImportWPCommonExporterExporterManager given, called in /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/class/Pro/Rest/RestManager.php on line 23 and defined in /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Common/Rest/RestManager.php:62
Stack trace:
#0 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/class/Pro/Rest/RestManager.php(23): ImportWPCommonRestRestManager->__construct()
#1 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/class/Pro/ServiceProvider.php(71): ImportWPProRestRestManager->__construct()
#2 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Container.php(69): ImportWPProServiceProvider->__construct()
#3 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Container.php(51): ImportWPContainer->maybeAddProvider()
#4 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/ImportWP.php(24): ImportWPContainer->setupServiceProviders()
#5 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/class/Pro/ImportWPPro.php(11): ImportWPImportWP->__construct()
#6 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/setup-iwp-pro.php(10): ImportWPProImportWPPro->__construct()
#7 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/setup-iwp-pro.php(79): import_wp_pro()
#8 /homepages/8/d4297389783/htdocs/wordpress/wp-includes/class-wp-hook.php(324): iwp_pro_loaded()
#9 /homepages/8/d4297389783/htdocs/wordpress/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#10 /homepages/8/d4297389783/htdocs/wordpress/wp-includes/plugin.php(517): WP_Hook->do_action()
#11 /homepages/8/d4297389783/htdocs/wordpress/wp-settings.php(578): do_action()
#12 /homepages/8/d4297389783/htdocs/wordpress/wp-config.php(186): require_once(‘/homepages/8/d4…’)
#13 /homepages/8/d4297389783/htdocs/wordpress/wp-load.php(50): require_once(‘/homepages/8/d4…’)
#14 /homepages/8/d4297389783/htdocs/wordpress/wp-login.php(12): require(‘/homepages/8/d4…’)
#15 {main}
thrown

Could you please check if this may be caused by some coding that is not up to current PHP standards? Restoring the site to PHP 8.0 fixes the problem immediately.

BR
Tim

James replied Support Agent

2 weeks ago on July 16, 2025 at 1:47 pm

Hi Tim,

Can you make sure you have the most upto date versions of import wp and import wp pro, as the error you mention suggests that there is a missalignment.

Import WP Pro (latest version can be downloaded from codecanyon): v2.11

Import wp (latest version can be downloaded from wp.org: https://wordpress.org/plugins/jc-importer/): 2.14.12

James

Tim replied

2 weeks ago on July 18, 2025 at 9:16 am

Hi James,

I can confirm that the most recent versions of the plugins are installed, compare to screenshot below.

Version 2.14.12 is also mentioned in the original error log.

2 weeks ago on July 18, 2025 at 9:20 am

Tried it again with PHP 8.1, just to confirm. Still the same error, thrown by Import WP.

Um deine Website zu schützen, läuft dieser Link in 1 Tag ab. Aber keine Sorge: Ein neuer Link wird dir per E-Mail zugeschickt, wenn der Fehler nach Ablauf der Frist erneut auftritt.

Wenn du Hilfe bei diesem Problem suchst, wirst du möglicherweise nach einigen der folgenden Informationen gefragt:
WordPress-Version 6.8.2
Aktives Theme: Hello Elementor (Version 3.4.4)
Aktuelles Plugin: Import WP (Version 2.14.12)
PHP-Version 8.1.33

Fehler-Details
==============
Ein Fehler vom Typ E_ERROR wurde in der Zeile 14 der Datei /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Common/UI/ViewManager.php verursacht. Fehlermeldung: Uncaught TypeError: ImportWPCommonUIViewManager::__construct(): Argument #1 ($properties) must be of type ImportWPCommonPropertiesProperties, ImportWPCommonPropertiesProperties given, called in /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/ServiceProvider.php on line 83 and defined in /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Common/UI/ViewManager.php:14
Stack trace:
#0 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/ServiceProvider.php(83): ImportWPCommonUIViewManager->__construct()
#1 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/class/Pro/ServiceProvider.php(54): ImportWPServiceProvider->__construct()
#2 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Container.php(69): ImportWPProServiceProvider->__construct()
#3 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/Container.php(51): ImportWPContainer->maybeAddProvider()
#4 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/jc-importer/class/ImportWP.php(24): ImportWPContainer->setupServiceProviders()
#5 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/class/Pro/ImportWPPro.php(11): ImportWPImportWP->__construct()
#6 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/setup-iwp-pro.php(10): ImportWPProImportWPPro->__construct()
#7 /homepages/8/d4297389783/htdocs/wordpress/wp-content/plugins/importwp-pro/setup-iwp-pro.php(79): import_wp_pro()
#8 /homepages/8/d4297389783/htdocs/wordpress/wp-includes/class-wp-hook.php(324): iwp_pro_loaded()
#9 /homepages/8/d4297389783/htdocs/wordpress/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#10 /homepages/8/d4297389783/htdocs/wordpress/wp-includes/plugin.php(517): WP_Hook->do_action()
#11 /homepages/8/d4297389783/htdocs/wordpress/wp-settings.php(578): do_action()
#12 /homepages/8/d4297389783/htdocs/wordpress/wp-config.php(186): require_once('/homepages/8/d4...')
#13 /homepages/8/d4297389783/htdocs/wordpress/wp-load.php(50): require_once('/homepages/8/d4...')
#14 /homepages/8/d4297389783/htdocs/wordpress/wp-login.php(12): require('/homepages/8/d4...')
#15 {main}
thrown

1 week ago on July 21, 2025 at 7:58 pm

Sorry for the delay in getting back to you.

I have created a fresh install with the same versions of plugins and also jetengine, and importwp jet engine plugin on php8 , 8.1 and 8.2 without any errors.

To help debug this can you create a new blank wordpress website starting fresh from php 8.1, and install importwp and importwp pro to see if the errors happen and let me know the results.

1 week ago on July 23, 2025 at 8:11 pm

once I find the time I will let you know and report back!

Possibly there could also be an error with another plugin. Should the issue not persist with a clean install I will try to force it again and extract the logs from Wordpress.

BR
Tim

1 week ago on July 24, 2025 at 7:37 am

Thanks Tim,

The reason i would like to see it on a fresh install is that many hosting companies have very extreme php caches, i was thinking that when you switched php version maybe there was a stale cache causing the errors.