It seems after upgrade the 2 elements form hierarchy element and form data exchange are not available in Composer V12.1
Perform below steps in order to resolve this issue.
1) Go to IIS
2) Explore the composer site
3) GO to the web config file of composer and open it in notepad
Search for the following values:
<add key="onNPIFeatureParentChild" value="False" />
<add key="onNPIFeatureCopyTableData" value="false" />
<add key="onNPIFeatureRepeatingWebService" value="false" />
<addkey="onNPIFeatureRepeatingWebServiceBulkUpload" value="false" />
Set its value to "true" and then save it.
Do an iisreset and rerun the composer and then rerun the scenario.
4) If that doesnt resolve issue please revert the values to false.