Symptom Quick Reference
Use this table to jump to the right fix based on the error you are seeing:1
Verify Entity Type References
Every relationship must reference valid entity type names in its
from and to fields. These names must exactly match keys defined under domainModelTypes, including capitalization.2
Check Navigation Property Names
The 
direct and back sections each contain a name field that creates a navigation property on the respective entity type. These navigation property names are what you use in column binding paths and source expansion paths throughout the sheet configuration.direct.name— creates a forward navigation property on thefromentity type (navigates toward thetoentity)back.name— creates a reverse navigation property on thetoentity type (navigates back toward thefromentity)
3
Align Sources with Navigation Names
The One-to-many (1:N) — collection expand:Many-to-many (M:N) — two-level expand through association:
expand entries in your sheet configuration sources must exactly match the navigation property names defined by direct.name or back.name in the data model. A mismatch here is one of the most common causes of empty expansion results.Many-to-one (N:1) — single-level expand:4
Verify the Link Role
The To find valid link role IDs, go to Administration > Work Items > Link Roles in Polarion. The ID column shows the value to use in your data model YAML.
linkRole must match a link role ID defined in your Polarion project configuration, not its display name.5
Validate Cardinality
The
cardinality value must match the actual relationship between your entity types. Using the wrong cardinality causes incorrect UI behavior — columns that should allow multiple selections only show one value, or vice versa.6
Fix Multi-Item Column Declarations
When a parent entity links to multiple work item types (for example, a
SystemRequirement linked to both DesignRequirement and DesignVerification), the second linked column must include multiItem: true in the sheet configuration. This is a non-obvious requirement that frequently blocks first-time configurations.7
Validate the Complete Configuration Chain
After making corrections, verify the full chain from data model through sources to columns:
- Data model — confirm
from/tomatchdomainModelTypeskeys,linkRoleis a valid Polarion link role ID, and bothdirect.nameandback.nameare present - Sources — confirm each
expandname matches a navigation property name from the data model, and many-to-many expands have two levels - Columns — confirm column binding paths use the correct dot-notation from the expand chain, and
multiItem: trueis set where needed - Storage — confirm
storage: linkedWorkItemsis used for Polarion link-based relationships
Verification
After correcting the relationship configuration:- Save the data model YAML in Administration > Nextedy Powersheet > Data Models
- Open a powersheet document that uses this data model
- Expand a row with related entities
- You should now see child entities appearing correctly under the expansion path, and the reference picker columns displaying valid choices
See Also
- Configure a Relationship — complete relationship setup guide
- Create Bidirectional Links — setting up two-way navigation
- Configure Many-to-Many Relationships — many-to-many relationship configuration
- Fix Multi-Item Column Errors — troubleshooting multi-item column issues
- Fix Type Name Errors — resolving entity type naming mismatches
- Data Model Reference — complete data model YAML reference