The error received is an expected NetSuite behavior. To avoid this, filter out the leads or prospects that the workflow is working on.
Solution
1. Create a Custom Entity Field
1. Navigate to Customization > Lists,Records, & Fields > Entity Fields > New
2. Label: Enter Label
Example: Custom Check Box
3. Type: Select Check Box
4. Store Value: Enter Checkmark
5. Click Applies To
6. Customer: Enter Checkmark
7. Click Save
2. Edit the Workflow
1. Navigate to Customization > Workflow > Workflows
2. Necessary Workflow: Click Edit
3. Click State with the Send Campaign Email
4. Click New Action
5. Click Set Field Value
6. Basic Information:
- Trigger On: Select Entry
7. Parameters:
- Field: Select Custom Check Box
8. Value:
- Value: Select Static Value
- Checked: Enter Checkmark
9. Insert Before: Select Send Campaign Email
10. Click Save
11. Click Send Campaign Email
12. Condition:
- Field: Select Custom Check Box
- Compare Type: Remove Checkmark
13. Click Save