Let's deal with this use case using an example:
Submit order: 
             -productid=B 
             -action=UPDATE

After submitting this order, plan generation fails and below errors are logged:
===
20 juil. 2022 18:37:29,111 ERROR [] [ORDER_2] [Member1] [com.tibco.aff.aopd.types.plan.PlanItem] [setMainPlanFragments] - [ThreadID:221] [Tenant ID:TIBCO] Planfragment mapping not found in the product Model [B] and action [UPDATE]in Main or Affinity Plan fragments. 
20 juil. 2022 18:37:29,166 ERROR [] [ORDER_2] [Member1] [com.tibco.aff.aopd.engine.RuleExecutionController] [generateAOPDPlanReply] - [ThreadID:221] [Tenant ID:TIBCO] Exception while creating execution plan while decomposing order for orderID [1075] , orderref  [ORDER_2] : [TIBCO-AFF-AOPD-100004] - Planfragment mapping not found in the product Model [B] and action [UPDATE]in Main or Affinity Plan fragments. : com.tibco.aff.aopd.rule.action.RuleExecutionException: PLANFRAGMENT_MAPPING_NOT_FOUND
        at com.tibco.aff.aopd.types.plan.PlanItem.setMainPlanFragments(PlanItem.java:1165)
        at com.tibco.aff.aopd.types.plan.PlanItem.setPlanItemFragments(PlanItem.java:1108)
        at com.tibco.aff.aopd.rule.action.PopulatePlanItemAction.setPlanItemData(PopulatePlanItemAction.java:144)

....
===

Please refer to the attached omsServer-local.log file for the full logs.

ALL

This issue occurred because of a misconfiguration in the catalog; there is no plan fragment associated to "UPDATE" action for the product "B" in  the catalog. Hereafter, a snippet of the catalog configuration:
===
<ns0:Product>
      <ns0:productId>B</ns0:productId>
      <ns0:description/>
      <ns0:owner/>
    </ns0:Product>
    <ns0:startDate>2021-11-17T20:31:54+05:18</ns0:startDate>
    <ns0:endDate>2021-11-17T20:31:54+05:18</ns0:endDate>
    <ns0:planFragments>
      <ns0:planFragmentUniqueId_CANCEL>
        <ns0:name>PF_CANCEL</ns0:name>
        <ns0:description>  CANCEL</ns0:description>
      </ns0:planFragmentUniqueId_CANCEL>
      <ns0:planFragmentUniqueId_PROVIDE>
        <ns0:name>PF_PROVIDE</ns0:name>
        <ns0:description>  PROVIDE</ns0:description>
      </ns0:planFragmentUniqueId_PROVIDE>
      <ns0:planFragmentUniqueId_CEASE>
        <ns0:name>PF_CEASE</ns0:name>
        <ns0:description>  CEASE</ns0:description>
      </ns0:planFragmentUniqueId_CEASE>
    </ns0:planFragments>
    <ns0:affinityPlanFragments>
      <ns0:planFragmentUniqueId_CANCEL>
        <ns0:name/>
        <ns0:description> AFFINITY CANCEL</ns0:description>
      </ns0:planFragmentUniqueId_CANCEL>
      <ns0:planFragmentUniqueId_PROVIDE>
        <ns0:name/>
        <ns0:description> AFFINITY PROVIDE</ns0:description>
      </ns0:planFragmentUniqueId_PROVIDE>
      <ns0:planFragmentUniqueId_CEASE>
        <ns0:name/>
        <ns0:description> AFFINITY CEASE</ns0:description>
      </ns0:planFragmentUniqueId_CEASE>
    </ns0:affinityPlanFragments>    
===   

So to fix the issue, configure UPDATE action for the product B and reload the catalog. See below example:

===
<ns0:Product>
      <ns0:productId>B</ns0:productId>
      <ns0:description/>
      <ns0:owner/>
    </ns0:Product>
    <ns0:startDate>2021-11-17T20:31:54+05:18</ns0:startDate>
    <ns0:endDate>2021-11-17T20:31:54+05:18</ns0:endDate>
    <ns0:planFragments>
    ...
      <ns0:planFragmentUniqueId_UPDATE>
        <ns0:name>PF_UPDATE</ns0:name>
        <ns0:description> UPDATE </ns0:description>
      </ns0:planFragmentUniqueId_UPDATE>
    </ns0:planFragments>
=== 

For more details, please refer to the attached Correct_PRODUCTMODEL.xml and Wrong_PRODUCTMODEL.xml files that show product B configuration.

This behavior is also valid for the other actions (cancel, provide, cease); if not properly configured, then this error will be encountered.
 

This KB article deals with plan generation failure due to the error: === [TIBCO-AFF-AOPD-100004] - PLANFRAGMENT_MAPPING_NOT_FOUND : com.tibco.aff.aopd.rule.action.RuleExecutionException: PLANFRAGMENT_MAPPING_NOT_FOUND ===