When customizing the Sales Order form, the Project or Job field is greyed out in the Screen Fields tab and cannot be set as Mandatory on the form. The user wants to make this field mandatory. This can be done by creating a workflow instead.
1. Navigate to Customization > Workflow > Workflows > New.
2. Set the following:
Record Type = Transaction
Sub Types = Sales Order
Release Status = Released
Trigger Type = On Create, On Update
3. Click on Save.
4. Create a New State > Click on Save.
5. Click on New Action > Select Set Field Mandatory
6. Set the following:
Trigger On = Before Record Load
Event Type = Create, Edit
Parameters: Field = Job (Main)
Mandatory = checked
7. Click on Save.
Note: The Project/Job field on the Sales Order form is available when Advanced Project feature is enabled in Setup > Company > Enable Features > Company tab.