During branch onboarding, if branch is deployed in azure enviroment check the OS during image creation.

By default its windows, flexvnf can be deployed on linux OS type only.

Check the vnms-azure.log

It will display below error

{

  "error" : {

    "code" : "InvalidParameter",

    "message" : "The value of parameter linuxConfiguration is invalid.",

    "target" : "linuxConfiguration"

  }

}

Change the OS type to linux and re-deploy the branch.