Plesk WP Toolkit “Unable to get site administrator settings” Error Fix (stdClass TypeError in WP_User_Query

[Aior]

Plesk WP Toolkit Unable to get site administrator settings Error Fix (stdClass TypeError in WP_User_Query)​

Overview​

This article explains a critical issue in Plesk WP Toolkit where administrator information cannot be retrieved and the following error appears:

Unable to get site administrator settings:

PHP Warning: Object of class stdClass could not be converted to int

PHP Fatal error: Cannot access offset of type stdClass on array

The problem may occur even when the WordPress frontend and admin panel work normally. In most cases, the failure only appears inside WP Toolkit.

Symptoms​

• WP Toolkit shows “Unable to get site administrator settings”
• WordPress frontend works normally
• WordPress admin panel works normally
• wp-cli commands work manually
• Error appears only inside WP Toolkit

Root Cause​

The issue is caused by a mismatch between PHP environments and cached query data.

• WP Toolkit uses a different PHP binary than system CLI
• CloudLinux alt-php behaves differently than Plesk PHP
• Redis object cache may return corrupted data
• WP_User_Query receives stdClass instead of expected array

Example mismatch:

WP Toolkit PHP:
/opt/alt/php84/usr/bin/php

Manual CLI PHP:
/usr/bin/php
/opt/plesk/php/8.3/bin/php

This difference causes inconsistent behavior and triggers fatal errors.

Technical Explanation​

WordPress uses WP_User_Query to retrieve users.

If query filters or cache return incorrect data:

• stdClass is returned instead of array
• PHP 8+ strict typing triggers fatal error

Common problematic hooks:

users_pre_query
pre_user_query

Step 1 Check PHP CLI MySQL Support​

php -m | grep -E 'mysqli|pdo_mysql|mysqlnd'

If missing:

dnf install -y php-mysqlnd

Expected:

mysqli
mysqlnd
pdo_mysql

Step 2 Verify WP CLI Works​

wp --allow-root user list

Also test:

wp --allow-root --skip-plugins user list
wp --allow-root --skip-themes user list

Step 3 Reproduce WP Toolkit Environment​

plesk ext wp-toolkit --wp-cli -instance-id 2 -- user list --role=administrator --format=json

If this fails but normal wp works, the issue is environment specific.

Step 4 Identify PHP Difference​

Check which PHP WP Toolkit uses.

Example:

/opt/alt/php84/usr/bin/php

Different PHP environments may load different extensions and cache behavior.

Step 5 Verify WP Toolkit Instance​

plesk ext wp-toolkit --list
plesk ext wp-toolkit --info -instance-id 2

If instance is Working but admin data fails, issue is cache or runtime related.

Step 6 Clear WP Toolkit Cache​

plesk ext wp-toolkit --clear-cache -instance-id 2
systemctl restart sw-engine
systemctl restart psa

Step 7 Disable Redis Temporarily​

wp --allow-root plugin deactivate redis-cache

Then test:

plesk ext wp-toolkit --wp-cli -instance-id 2 -- user list --role=administrator --format=json

Step 8 Flush Redis Cache​

Check Redis:

redis-cli PING

Expected:

PONG

Flush cache:

redis-cli FLUSHALL

Expected:

OK

Step 9 Reactivate Redis Carefully​

wp --allow-root plugin activate redis-cache

Test again:

plesk ext wp-toolkit --wp-cli -instance-id 2 -- user list --role=administrator --format=json

If it fails again, Redis configuration is incompatible.

Step 10 Review Custom Plugins​

Check plugins affecting:

• user queries
• gettext filters
• global query hooks
• object caching
• admin hooks

High risk patterns:

• users_pre_query usage
• pre_user_query usage
• metadata query manipulation
• translation or output interception plugins

Test by disabling plugins one by one.

Step 11 Optional Deep WP Toolkit Reset​

rm -rf /usr/local/psa/var/modules/wp-toolkit/*
systemctl restart sw-engine

Safe Troubleshooting Flow​

1. Check CLI PHP MySQL extensions
2. Verify wp-cli works
3. Reproduce WP Toolkit error
4. Clear WP Toolkit cache
5. Disable Redis
6. Flush Redis
7. Retest WP Toolkit
8. Reactivate Redis carefully
9. Check custom plugins

Key Insight​

This is not a WordPress core bug.

It is caused by:

• environment mismatch
• cache corruption
• PHP strict typing

Conclusion​

This issue follows a clear pattern:

• WordPress works normally
• WP Toolkit fails
• different PHP environments are used
• cached data causes type errors

By aligning PHP environments and resetting cache layers, the issue can be fully resolved.

This approach ensures stable WP Toolkit operation in CloudLinux and Plesk environments.