What does this error mean?

Error executing databse query

[Macromedia][SQLServer JDBC Driver]Syntax error at token 0, line 0 offset 0.

Here is my code:

<!--- new array --->
<cfset users = ArrayNew(1)>
<cfset IDsToDelete = "">

<!--- populate array via loop --->
<cfloop from="1" to="#qNumberOfRecords.RecordCount#" index="i">
<cfset sub_id = Trim(qNumberOfRecords.sub_id)>
<cfset group_id = Trim(qNumberOfRecords.group_id)>

                 <!--- Master query to perform all operations --->
                 <cfquery name="qMaster" datasource="#Application.dsn#">
                 <!--- execute queries based on array length --->
                 <cfloop from="1" to="#ArrayLen(users)#" index="j">
                    UPDATE  SUBSCRIPTION
                    SET group_id = '#group_id#'
                    WHERE sub_id = #sub_id#<!---in (SELECT #tableName#.sub_id FROM #tableName#)--->;
                   
                   
                   
                    <!--- delete user from Account_User_Group table --->
                    DELETE FROM ACCOUNT_USER_GROUPS
                    WHERE sub_id = some_value

                   
                   
                   
                            <!--- insert users into ACCOUNT_USER_GROUPS --->
                            <cfloop from="1" to="#ListLen(users.sub_group_id)#" index="k">
                                INSERT INTO ACCOUNT_USER_GROUPS
                                   (sub_id,
                                    group_id,
                                    account_id,
                                    active)
                                VALUES
                                   (<cfqueryparam cfsqltype="cf_sql_integer" value="#users.sub_id#" />,
                                    <cfqueryparam cfsqltype="cf_sql_integer" value="#ListGetAt(users.group_id, k)#" />,
                                    '291',
                                    '1');
                            </cfloop><!--- close k loop --->
                  </cfloop><!--- close j loop --->
                  </cfquery><!--- close qMaster query --->