Solusvmpro module does not support PHP 8.x

Symptoms 

Solusvmpro module does not support PHP 8.x:

CONFIG_TEXT: PHP Fatal error: Array and string offset access syntax with curly braces is no longer supported in /home/risingnet/secure.risingnet.com/httpsdocs/crm/modules/servers/solusvmpro/lib/SolusVM.php on line 234
Fatal error: Array and string offset access syntax with curly braces is no longer supported in /home/risingnet/secure.risingnet.com/httpsdocs/crm/modules/servers/solusvmpro/lib/SolusVM.php on line 234
[WHMCS Application] ERROR: Whoops\Exception\ErrorException: Array and string offset access syntax with curly braces is no longer supported in /home/risingnet/secure.risingnet.com/httpsdocs/crm/modules/servers/solusvmpro/lib/SolusVM.php:234 Stack trace:#0/home/risingnet/secure.risingnet.com/httpsdocs/crm/vendor/whmcs/whmcs-foundation/lib/Utility/Error/Run.php(0): WHMCS\Utility\Error\Run->handleError()#1[internal function]: WHMCS\Utility\Error\Run->handleShutdown()#2{main} {"exception":"[object] (Whoops\\Exception\\ErrorException(code: 64): Array and string offset access syntax with curly braces is no longer supported at /home/risingnet/secure.risingnet.com/httpsdocs/crm/modules/servers/solusvmpro/lib/SolusVM.php:234)"} []
Whoops\Exception\ErrorException: Array and string offset access syntax with curly braces is no longer supported in /home/risingnet/secure.risingnet.com/httpsdocs/crm/modules/servers/solusvmpro/lib/SolusVM.php:234

#0/home/risingnet/secure.risingnet.com/httpsdocs/crm/vendor/whmcs/whmcs-foundation/lib/Utility/Error/Run.php(0): WHMCS\Utility\Error\Run->handleError()
#1[internal function]: WHMCS\Utility\Error\Run->handleShutdown()
#2{main}

Cause

SolusVM bug with ID #SVM-3619 which was fixed in SolusVMpro module version 4.2.1

Resolution

Update SolusVM provisioning module to the latest version