Paginated reports error - getting data from semantic model

Hii ahmedshalabyy12 

For this error 

Step 1: Check Workspace Version and Permissions

​Paginated reports require specific workspace configurations.

• ​Workspace Type: Ensure Workspace A is a V2 (New) workspace. Legacy V1 workspaces can cause retrieval errors.
• ​Permissions: Confirm you have Member or Admin roles in Workspace A. Even if you can see it in the service, Report Builder requires higher-level permissions to browse the semantic models.
• ​Build Permission: Ensure you have "Build" permissions on the specific semantic model you are trying to reach.

​Step 2: Re-authenticate the Session

​Sometimes the local token for one workspace becomes "stale" or corrupted.

1. ​Close Power BI Report Builder.
2. ​Go to File > Options (if accessible) or simply Sign Out from the top-right corner.
3. ​Restart your computer to clear any cached network credentials.
4. ​Open Report Builder and Sign In again before attempting to connect to the dataset.

​Step 3: Check for "Broken" Semantic Models

​The NullReferenceException is often triggered by a single "corrupt" or "orphaned" dataset in a workspace.

• ​Log into the Power BI Service and look at Workspace A.
• ​Check if there are any datasets with a red alert icon (Gateway disconnected or credentials expired).
• ​If a dataset in Workspace A has no owner (owner left the company), it can return a "Null" value to the Report Builder API, crashing the entire list retrieval for that workspace.

​Technical Summary

​The stack trace points to IsMyWorkspace failing. This usually happens when the workspace contains an object that Report Builder cannot categorize, such as a dataset without a valid owner or a workspace that has not been upgraded to the modern experience.

​If checking the workspace owner or re-signing in fixes the connection for Workspace A, please mark this as the "Accepted Solution"!