Power BI error " Cube Table must have exactly one island"

[marduk20]

Hi PBI community,

Has anyone of you already encountered this error " Cube Table must have exactly one island"?

Can you help further understand

[MarkyMark1 · Accepted solution]

I had the same issue. It resolved when I added new features in the preview features and restarted Power BI. I think it was Store semantic model using TMDL format and Enhanced publish dialogs features

[boley2131]

I'm getting the same error message, but this is what I've diagnosed so far:

In my case, I'm connecting my Power BI report to a table in a different report via OneLake data hub.  After I upgraded to the February release, when I refresh I now get this error message.  I have deleted the dataset connection and try to re-create it, but when I try to connect to the semantic model as a new connection, it gives me the error.

This runs perfectly fine in the December version.

[DWay]

I've been experiencing the same problem and I think I've narrowed it down to referencing another semantic model.  I'm reusing a colleague's semantic model and all was working just fine in early Feb 2024.  I thought the problem might have been due to the fact that I was renaming the tables since reverting to the original names seemed to have fixed the problem.  I asked my colleague to rename the tables to be more unique (he had a table named "ALL") and now I can't workaround the problem at all.

I'm now wondering if I'm using the old table names somewhere else in my project like in a measure.

[wkqdbig]

I'm in the same boat - referencing two semantic models, this worked absolutely fine before. How do we go about getting this flagged to Microsoft for fixing? Rolling back isn't an option if they're building on top of this new constraint. 

[yzc]

I also encounterred the same error today. Could it be a bug in recent update? 

My report was running very smoothly just 2 weeks ago. After a 2-week holiday it told me "Cube Table must have exactly one island" and I can no longer refresh my report.

I hope microsoft could fix this soon.

[J1298]

having the same issue:  The dec 2023 did not have this issue.  Now some pc's have gotten the new febr 2024 update,  and now this error is showing on a couple of laptops. The report is still working on pc's(lt's) with the dec 2023 version. During time updates rolling in,  now having this issue.  1 Exception,  my (owner of the report) LT is still working, with a manual install of the feb 2024 version. Further:  My install is English, the others with feb 2024 version and in trouble, have local language installs.

Looked in the logs, but could not find anything strange or related to this error, what I could check.

So, questions:

- is it dependent on the local language  (not English)

- is it App versus local install  (tested it on 1 local language LT,  both issues)

- is there a bug within PBI feb 2024 version related to "Cube tables must have exactly one island"

[J1298]

Reverted to the Nov 2023 version.  All issues solved.

Before checked on the Febr. 2024 version:

Removed all Relations.  (issue still there).

Removed 1 by 1 all tables.  Found 1 table, when removed, the issue was gone.  This table was still needed, so Issue solved, but report not useable. Could not detect anything wrong within this table (and applied steps).  Could not determine what was wrong with this table.

Then last chance:  reinstall Nov 2023 version.  Issue solved for now. 

@Microsoft  Please check the Feb 2024 version on this issue

[J1298]

As MS-Farnoud asked,  I DM-ed him to share some (non-confidential) information.  Waiting for Farnoud to respond.

[wkqdbig]

@Microsoft please fix, this is going backwards currently

[yzc]

Latest information: 

After trying again without changing anything, it worked. No error. 

So mysterious

[jst_jdennis]

Yes, I have encountered this error before in Power BI. The error message "Cube Table must have exactly one island" typically occurs when there are multiple disconnected tables or columns in a data model that are not related to each other. In other words, there are multiple "islands" of data that are not connected by any relationships in the model.

To fix this error, you will need to examine the relationships between the tables in your data model and ensure that all tables are connected to each other in a single "island" of data. Here are some steps you can follow to troubleshoot and fix the error:

1. Check your data model: Open your Power BI data model and examine the relationships between tables. Make sure that all tables are connected to each other in a single chain or loop of relationships, with no disconnected tables or columns.

2. Check for missing relationships: If you find a disconnected table or column, check to see if there is a missing relationship that should be connecting it to the rest of the data model. Add the missing relationship if necessary.

3. Check for circular relationships: If you have a circular relationship in your data model, where two tables are related to each other in a loop, this can also cause the "Cube Table must have exactly one island" error. To fix this, you will need to break the circular relationship by creating a new table that serves as a bridge between the two tables.

4. Check for inactive relationships: If you have multiple active relationships between tables in your data model, this can also cause the error. Make sure to deactivate any unnecessary relationships in the model.

5. Refresh the data model: After making any changes to your data model, make sure to refresh the data to ensure that the changes are applied.

By following these steps, you should be able to fix the "Cube Table must have exactly one island" error and create a data model with a single "island" of connected data.

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