Graphs not being displayed/distributed polling not working

I’m a relative noob to LibreNMS, and sadly the member of our team that configured it is on leave. We’re experiencing a couple issues, not sure whether or not they may be related:

  • Our graphs are not being displayed; instead we see the path to the graph displayed in the window, as below:

The pollers also aren’t checking in. This is the output of ./validate.php from the server:

===========================================

Component Version
LibreNMS 22.12.0-25-gd86b9ce88 (2023-01-21T07:17:43-06:00)
DB Schema 2022_08_15_084507_add_rrd_type_to_wireless_sensors_table (248)
PHP 8.2.1
Python 3.8.10
Database MySQL 8.0.30-commercial
RRDTool 1.7.2
SNMP 5.8
===========================================

[OK] Composer Version: 2.5.1
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database Schema is current
[OK] SQL Server meets minimum requirements
[OK] lower_case_table_names is enabled
[OK] MySQL engine is optimal
[OK]
[OK] Database schema correct
[OK] MySQl and PHP time match
[OK] Distributed Polling setting is enabled globally
[OK] Connected to rrdcached
[OK] Active pollers found
[FAIL] Some dispatcher nodes have not checked in recently
Inactive Nodes:
librenms-poller1
librenms-poller2
[OK] Locks are functional
[OK] Python wrapper cron entry is not present
[OK] Redis is functional
[OK] rrdtool version ok
[OK] Connected to rrdcached

And this is the output of ./validate.php from one of the pollers:

In PluginProvider.php line 38:

Class “App\Plugins\PluginManager” not found

====================================

Component Version
LibreNMS 22.9.0-3-g06c361c2b
DB Schema Not Connected (0)
PHP 8.2.1
Python 3.8.10
Database Not Connected
RRDTool 1.7.2
SNMP 5.8
====================================

[OK] Composer Version: 2.5.1
[OK] Dependencies up-to-date.

Checked the logs, and there are a ton of the following messages:

production.ERROR: Class “App\Plugins\PluginManager” not found {“exception”:"[object] (Error(code: 0): Class "App\Plugins\PluginManager" not found at /opt/librenms/app/Providers/PluginProvider.php:38