Error when dataset not available

When a module is called with `data_extract_spec`s that refer to datasets absent in the data, a warning is raised in the console.
```
Warning message:
Dataset `ADTTEE` is missing for module 'Regression Analysis'. Datasets available in data: `ADSL` and `ADAE`.
```

This is a warning, not an error. However, when one proceeds to run the app regardless, the app will raise an error:


The encodings remain responsive, I can even attempt to select a variable from the absent dataset but there are no choices, which is safe.


Is this condition upgrade intended? Would it be possible to allow the app to run without all specified datasets?