New fields are not available in expressions on existing workflows

[vlad610]

Bug Description

In workflows, when you try to use an expression to update a field on a specific record, newly created fields (created after the workflow was created) are not available to be selected as a value.

Steps to reproduce:

1. Create a workflow that runs on Tasks Create event, without actions
2. Save the workflow
3. Add a new field on the Task object
4. Edit the workflow created at step 1 and add an action of type "Create Record: Task"
5. Try to use an expression to set the value of a field.
6. Notice the new field you created at step 3 does not show up in the list of fields available to be selected in the expression

Expected behavior

All fields should be selectable in the expression at all times.

Workaround

Re-create the workflow. The new field will be available to be selected inside expressions.