Error "Error creating config item"

The problem

When adjusting the “Ignore alert tag” in the “Port Settings”, I receive the error “Error creating config item”. The error occurs on every device.

Output of ./validate.php

===========================================
Component | Version
--------- | -------
LibreNMS  | 26.9.1-dev.5+d0d54f0c7 (2026-08-24T17:55:49+02:00)
DB Schema | 2026_07_30_162514_add_device_refresh_config_permission (397)
PHP       | 8.4.24
Python    | 3.11.2
Database  | MariaDB 10.11.18-MariaDB-0+deb12u1
RRDTool   | 1.7.2
SNMP      | 5.9.3
===========================================

[OK]    Composer Version: 2.10.2
[OK]    Dependencies up-to-date.
[OK]    Database Connected
[OK]    Database Schema is current
[OK]    SQL Server meets minimum requirements
[OK]    lower_case_table_names is enabled
[OK]    MySQL engine is optimal
[OK]    Database and column collations are correct
[OK]    Database schema correct
[OK]    MySQL and PHP time match
[OK]    Active pollers found
[OK]    Dispatcher Service not detected
[OK]    Locks are functional
[OK]    Python poller wrapper is polling
[OK]    Redis is unavailable
[OK]    rrd_dir is writable
[OK]    rrdtool version ok

What was the last working version of LibreNMS?

26.9.1-dev.5+d0d54f0c7