It seems like it may be language related. To reproduce, manage a SolusVM service as admin or client and click on Stats or Server Actions. Occurs on at least PHP 8.2 and 8.1. Probably related to language in some way.
The following error is produced:
general-error-2024-10-04.log <==
[2024-10-04T17:22:24.411562+00:00] general.ERROR: Uncaught Exception ValueError: "Missing format specifier at end of string" at /home/blestau/public_html/511dev/vendors/minphp/language/src/Language.php line 125
{"exception":"[object] (ValueError(code: 0): Missing format specifier at end of string at /home/blestau/public_html/511dev/vendors/minphp/language/src/Language.php:125)"}
Update the line for the language definition for Solusvm.!percent.used in /components/modules/solusvm/language/en_us/soluvm.php
$lang['Solusvm.!percent.used'] = '%1$s'; // %1$s is a percentage value