When launching Composer from an Opportunity the OpplineItems dataset is not in the Template Builder or View Data Workbook.
It is likely that fields with nearly identical API field names are present on the Opportunity Product Object.
For example, if you create a custom field with an API name of Quantity__c on the Opportunity Product object, Composer will try to create two fields with the name Quantity because there is also a standard field on the Opportunity Product called Quantity. When Composer tries to create the same field name in the Template Builder twice, the entire dataset is omitted.
While this data does not display in the Template Builder, it will still merge successfully into an output document.
What to Do
There are two known solutions:
- Rename the API Field Name of the duplicate field.
Exercise caution when renaming API Field Names. This can cause field names to change in the Template Builder, which means any template that references the old field name would need to be updated.
- Another workaround is to rebuild the standard OpplineItems dataset using a Conga Query.