HDIV error in forEach inside form select

I'm having trouble trying to implement form:select in HDIV. Here's my code in the JSP which renders the selector and options:

<form:form
        modelAttribute="staffPosition" 
        method="post"
        action="${contextPath}/project/assign/staff">
        <td>
                <form:select class="form-control" path="staffID">
                        <c:forEach items="${staffList}" var="staff">
                                <c:set var="staffName" value="${staff.prefix} ${staff.firstName} ${staff.middleName} ${staff.lastName} ${staff.suffix}"/>
                                <form:option value="${staff.id}" label="${staffName}"/>
                        </c:forEach>
                </form:select>
        </td>
        <td>
                &nbsp;
        </td>
        <td>
                <form:input placeholder="Example: Project Manager, Leader, etc..."
                        type="text"
                        class="form-control"
                        path="position"/>
        </td>
        <td>
                &nbsp;
        </td>
        <td>
                <button class="btn btn-default btn-flat btn-sm">Assign</button>
        </td>
</form:form>

After I click assign and initiate the action, the request would arrive in the Controller with the correct ID of the selected form:option.

public String assignStaff(
        @ModelAttribute(ATTR_STAFF_POSITION) StaffAssignmentBean staffAssignment) {

However, when I inspected the console, there was an error: INVALID_CONFIDENTIAL_VALUE;/pmsys/project/assign/staff;staffID;27;[27, 28, 29, 30, 31, 32, 41];127.0.0.1;127.0.0.1;root

When I tried to trace the line of code which spits out the error: org.hdiv.filter.ValidatorHelperRequest:948

There was an inconsistency with the originalValue and the parameter value when this condition was evaluated: if (!m.matches() || (Integer.valueOf(value).intValue() >= stateValues.size())) {

originalValue = [27, 28, 29, 30, 31, 32, 41]

value = 27 (This is the ID number of the form:option which I selected in the JSP)

Does anyone have any solution to this problem? Could this be a bug in HDIV?

Note: This problem does not occur if I do not have a <c:forEach inside <form:select.