Occasionally there may be a condition where an attribute is not present in all classes hierarchy of children classes (CMDB - Class Manager), but it is present in the definition of its parent. 
Specifically, while using the CMDB Class Manager you might see an attribute listed under BaseElement, but missing when looking at any child class.

For example, BMC_ComputerSystem class missing the "TokenId" attribute.

This type of problem may only become visible when CIs are queried in class containers (i.e. BMC.CORE:BMC_ComputerSystem versus BMC.CORE:BMC_BaseElement) that have the attribute missing.

For example, if the Reconciliation Engine Identification rule tries to find a match based on that attribute. If the attribute definition did not propagate properly to all child classes then this would become impossible for Reconciliation to apply the rule. This is a problem that needs to be resolved.

For example, an AR query searches with this scope from BMC.CORE:BMC_ComputerSystem schema:

'TokenId' != $\NULL$ and 'TokenId' = $TokenId$

If the attribute is not properly inherited in the Common Data Model (CDM) then you'd see an error in the log as an error saying that the field (column) does not exist.
That's just one use case of the symptom and there can be other scenarios where a missing column error can be seen in logs.

Another example is that you may find the attribute "isVirtual" is absent from the BMC_Printer and BMC_Mainframe class, but it is present in all of their parents.
This may seem logical at first because Printer or Mainframe can not be virtual, but the fact is that all attributes found in parent classes must be also found in all their child classes.

The conditions under which missing attributes would occur are usually related to the time frame when the synch process gets interrupted by some resource means, such as Out of Memory error during the CDM synchronization or resource-intensive interaction with the ARS Server by a user that is not aware of this administrative task being performed. Basically interrupting the synch process would cause this.

These are just some ideas on how to identify this condition in your environment, but not limited to just these two examples.

Legacy ID:KA364183

Here are steps on how you can resolve this:

First exit all clients such as Developer Studio and User Tool.
Basically, anything that can be used to interact with the CDM. Please keep in mind that BMC Developer Studio for AR Server should never be used for BMC.CORE class administration.

1. Find the instructions to start and login into ARS with the cmdbdriver (AtriumCore Administration Guide).
   
The Sequence of commands to login into the cmdbdriver utility should be:
"init",
"log",
"ssp" (only if you are not using portmapper),
"ssc" (Set Configuration Settings [ option 2 and then 7200 for the time out of 2 hours. *1 see note])

2. Run this command once the cmdbdriver has been initialized:

Command: xexpdf
XEXPORT DEFINITION
Export all classes? (F): T
Export all attributes with classes? (T):
Filename for exported data: CDM.xml

   CMDBXExportDef  results
ReturnCode:  OK
Status List : 0 items
 

This will produce an export of the entire CDM into an xml formatted file that has more or less ~50,000 lines or so.

*LET'S MAKE THIS EASY NOTE: 
In Unix only you can push the cmdbdriver into "background" by typing CTRL-Z and then type "bg". To bring it back "forward" you can then type "fg".
This will allow you to do the next steps without having to exit the cmdbdriver process completely.

3. Using VI editor or some text editor (if Windows) reduce the file to just the set of attribute definition(s) you need to restore.

Please keep in mind that you need to restore the attribute from the class that "owns" it. So, in this example we would do this with the BMC.CORE:BMC_System class. (not BMC_Printer or BMC_Mainframe).

The contents of that file will now need to be reduced to just that attribute definition.
Start from line 1 and follow the "Instruction set" in caps (not including the lines in CAPs show only as "Instruction set").

Example of final result:

<?xml version="1.0" encoding="utf-8"?>                            
<cmdbDefinitionList xmlns="urn:remedy:schemas:cmdb" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:remedy:schemas:cmdb cmdbdef.xsd" cmdbDocVersion="3">

REMOVE ALL LINES STARTING FROM THE 2 ABOVE LINES ALL THE WAY TO THE "attribute" TAG. << Instruction set

 <attribute>
  <classNameId>
   <namespaceName>BMC.CORE</namespaceName>
   <className>BMC_System</className>
  </classNameId>
  <definition xsi:type="enumeration">
   <attributeName>isVirtual</attributeName>
   <attributeId>OS00C04FA081BAbMXaSAaq6rlgre4A</attributeId>
   <fieldId>530054200</fieldId>
   <entryMode>optional</entryMode>
   <defaultValue>
    <nullValue/>
   </defaultValue>
   <characList>
    <attributeViewPermissions>
     <groupId>-1098</groupId>
     <groupId>-1090</groupId>
    </attributeViewPermissions>
    <attributeChangePermissions>
     <groupId>60513</groupId>
     <groupId>-1099</groupId>
     <groupId>-1091</groupId>
    </attributeChangePermissions>
    <hidden>false</hidden>
    <primaryKey>false</primaryKey>
    <createMode>allowAnyUserToSubmit</createMode>
    <auditType>none</auditType>
    <namespace>BMC.CORE</namespace>
    <description>Attribute that specifies whether the instance is virtual or physical. To ensure correct reconciliation with data created by BMC Software products, use NULL instead of No for an instance that is not virtual.</description>
    <isDeprecated>false</isDeprecated>
   </characList>
   <limits>
    <regular>
     <valueList>
      <value>No</value>
      <value>Yes</value>
     </valueList>
    </regular>
   </limits>
  </definition>
 </attribute>

REMOVE ALL LINES FROM THE CLOSING TAG "attribute" ALL THE WAY TO THE ONE BEFORE THE LAST LINE.   << Instruction set.

</cmdbDefinitionList>

Save the file now.

4. Return to cmdbdriver process ("fg" if Unix) and run an import of this def file:

Command: impdf
DEFINITION IMPORT
Import Item List:
Number of import items (0):
Import option : Create/Overwrite (1-2) (1): 2
Filename containing import data: example.xml

   CMDBImportDef  results
ReturnCode:  OK
Status List : 0 items
 

NOTE: This can take some time. Please be patient.

5. That is it. You're done. Check the CMDB Class Manager to verify that the attribute is now present in all children classes of the parent class.

(*1) If you need to load a large set of attributes then you will need to set a time out longer than the 5 minute default time out of the cmdbdriver.
For this you'll need to run the ssc command and set it to 7200 seconds (2 hours).

If you do not do this you might get a timeout error  94 (Time out during database query)

The following is the syntax to set the time out:

Command: ssc
SET SESSION CONFIGURATION
Session variable Id (0): 3
Datatype Null/Key/Int/Real/Char/Diary/Enum/Time/Bitmask/Byte/Decimal/
         attach/currency/date/timeofday/join/trim/control/Table/Column/
         ulong/coords/view/display (0-14, 30-34, 40-43) (2): 2
   Integer Value (0): 7200

   ARSetSessionConfiguration  results
ReturnCode:  OK
Status List : 0 items