Data merge with variables shared by multiple objects should not create errors
Assigning multiple objects to the same variable would be particularly useful for language translations, in which the same value should appear in different objects of the same document.
While the UI allows to link several objects to the same variable, Illustrator behaves badly in these cases:
When a new dataset is created, Illustrator will assign different values to the same variable and where the value shows up is unpredictable.
The exported variable library is invalid and cannot be imported again.
If a CSV is imported into such a document, the import fails with an unknown error, while the CSV import of the same table works in documents with single assignments.
The problem exists in version 22 as well as version 23 on MacOS 10.14
Vasily Hall commented
This is the Illustrator multi-variable one-way-trip. A variable can only be bound to multiple objects while inside the document. If using the variableimporter script, some of these problems are avoided - but one must import the entire CSV as adding a new dataset while working in the document is a no-go. The VI script can be set to bind variables to named objects which duplicates the variable to its many places automatically.
John Wyatt commented
This is driving me crazy right now too. What I'm trying to do is very simple and I get the same error even trying a work around where I have multiple columns with the same data value, but different variable names. This would save my team loads of time in making concept sheets where we can just edit the info in a google sheet and pass the data through into illustrator but at this point I don't think its possible. This bug really should be addressed as it makes this variable feature pretty impractical in use.