While creating a new action in flow designer with input variable type as object, making it to mandatory and loading the child variables from template, the parent variable is still mandatory and the mandatory radio button is getting greyed out.
1. Navigate to Flow Designer >Designer.
2. Click on New > Action.
3. Provide details like Name, Category, Application and description > Submit.
4. Click on Create Input.
5. Change the variable type to 'Object' and Make it mandatory by clicking on the radio button.
6. Click on Down Arron Key and Select Structure as 'Start from Template'.
7. Select the 'Template' from where you want to get the child variables.
This problem is under review and targeted to be fixed in a future release. To receive notifications when more information becomes available, subscribe to this Known Error article by clicking the Subscribe button at the top right of this form.
As a workaround it is suggested to not to make the current object type variable mandatory if trying to load the child variable inputs from template inside the custom flow action.