@bhuvi_kpmg You are not suppose to change the native Identity with email, because may be API does not understand the email in header as valid as it is expecting GUID.
Try to follow
- As your GUID is Application side attribute so please set as native Identity in create Response just read the GUID or all other attribute like u do in single account aggregation
- Check the APplication JSON attribute which is set as something like createAccwithend this need to be set As true
- Now create account and see functionlity is working.
It must work right now i guess in another call it is failing as email is not something api does understand as unique
If this is global kind of application then send me name or json