SLA Escalation =>> Data Transform D1 (sets param.pyModelName to D1) =>> Data Page DP1 =>> Data Transform D2 (doesn't set param.pyModelName to D2, and calls D1 to load DP1)
Whenever a data transform is called from a service level rule as an escalation step, the name of the data transform gets passed in the parameter "pyModelName". If the called data transform references any other rule, which need a different data transform (for example: refers a data page which gets data from another data transform), the same parameter "pyModelName" is used for passing the name of the second data transform. This parameter however doesn't get updated automatically hence the second call fails.
Workaround: Take the backup of parameter pyModelName at the beginning of first data transform D1 and either remove the param pyModelName or set it to the name of second data transform which should load the called data page. Towards the end of first data transform, set the parameter pyModelName from its backup.