ER Object Base Reference Error

When uploading versions to ER, you may sometimes encounter the error messages ‘Unresolved references left’ and ‘Reference of the object X to the object ‘Base’ Y cannot be established’. Let’s discuss why this happens, how to prevent it, and how to fix it.


Let’s suppose we have a Model, a Mapping, and a Format. The model is on version 1, the Mapping on 1.X, and the Format on 1.X. Then we decide to reuse the same Model and Mapping for another Format. However, we realize this new format requires an extra field. So, we modify the Model, now at version 2, we rebase and modify the Mapping to 2.X, and do the same for the new Format, now at 2.X:

In ER, the version number on the right indicates the version of that node. Next, on the left, is the version of the node it hangs from. Although a node may depend on more than one node, this example is straightforward.

Now, let’s say we want to keep a local copy of those ER nodes. So, we select the newest completed version of each and export them:

After that, we overwrite our environment with a database that doesn’t have those nodes (as ERs are saved in the database). Then, we upload our local copy to the environment.

We can upload all other nodes, but for the first format, we get the error ‘Unresolved references left’ and ‘Reference of the object “CNTS_FirstFormat” to the object “Base” ({A0756978-B4A7-40F1-91A5-E534DFAB631C},1) cannot be established’. That’s because our first format points to version 1 of our model, but we forgot to keep a copy of all references and we only made a local copy of the newest, version 2.


As a last resort, if there is no other way to recover our first model version, we may try modifying our format XML to pretend it’s from a higher version. Let’s open it, search for the GUID ‘A0756978-B4A7-40F1-91A5-E534DFAB631C’, and change the version 1 to 2, and the public version to 2.X.

Now, we can import it:







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