Assistance Required: Error While Deleting Leave Types

Hi,I am trying to delete various leave types from "Leave Type," but an error message appears (please see the attached screenshot).For your reference, also refer to a log file records as below. Your assistance is essential to resolving this issue.

2024-11-27 16:42:35.752 ***** ERROR ***** [V11.4.2] [19] Exception-[42000] SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
2024-11-27 16:42:35.753 ***** ERROR ***** [V11.4.2] [19]    For query : delete from assignment where refType = 'Activity' and refId = 
2024-11-27 16:42:35.753 ***** ERROR ***** [V11.4.2] [19]    Strack trace :
2024-11-27 16:42:35.754 ***** ERROR ***** [V11.4.2] [19]    #0 Sql->query called at [C:\Apache24\htdocs\projeqtor\model\persistence\SqlElement.php:2310]
2024-11-27 16:42:35.754 ***** ERROR ***** [V11.4.2] [19]    #1 SqlElement->purgeSqlElement called at [C:\Apache24\htdocs\projeqtor\model\persistence\SqlElement.php:1168]
2024-11-27 16:42:35.754 ***** ERROR ***** [V11.4.2] [19]    #2 SqlElement->purge called at [C:\Apache24\htdocs\projeqtor\model\LeaveTypeMain.php:589]
2024-11-27 16:42:35.755 ***** ERROR ***** [V11.4.2] [19]    #3 LeaveTypeMain->delete called at [C:\Apache24\htdocs\projeqtor\tool\deleteObject.php:77]

Note: ProjeQtOr Version, we are using is: 11.4.2