When building the Workflow feature, a schema is added, grouping the global variables that are edited within a node. But, if a widget on a node's form is bound to an non-existing field, a NPE is thrown and the project is not build.
To avoid this, we should implement a validation of the fields on each form of a workflow when saving.
Steps to reproduce:
- Create a workflow variable
- Use this workflow variable in a node's form tab
- Save the workflow
- Delete the workflow variable
- Save the workflow again