Here are reasons fields can be missing from Blueprints:
1. Any attribute that has a API Attribute ID that is blank and read only. This can be checked by the following steps:
- In the Classic UI, go to Administration->Studio->Objects->Project->Attributes
- Click on the attribute
- View the API Attribute ID
- If it is blank and read only, then it is unable to be added
2. The following attribute data types:
Adding the API Attribute ID to these attribute not supported and these field types are not able to be added to Blueprints. This is referenced in the Blueprint documentation at: Edit Blueprint Details, Visuals, and Modules
- Custom time-scaled value (TSV)
3. See the Blueprint Project Fields section in Edit Blueprint Details, Visuals, and Modules for a lit of named attributes that are not available to be included from the Project object.
- The list of attributes on the above page is not an all inclusive list
- Some example of attributes referenced that can't be added to Blueprints: % Complete Calculation Method, Approved, Progress, Status
4. In 15.3, custom attributes (outside the above exclusion of Custom time-scaled value (TSV), Attachments, and URL) cannot be added due to a defect fixed in 15.3 patch 1. See: KB000092718 - In the New UX, Unable to add Custom Attributes to Blueprints for more details.