Global id space is missing data

When using the neo4j admin import CSV tool I get:

global id space is missing data

for a couple (8 out of multiple 100k) of relations.
So far I could not figure out what the error is meaning or how to resolve it.

I know that using --skip-bad-relationships could be an option - but I would rather know that it works.

A visual inspection of these specific relationships was not conclusive so far.

Do you have any ideas what is wrong or what to check as a next step whilst debugging?

The logs look like:

<<<xxx>>> (Profile)-[Following]->null (global id space) is missing data

But the data is showing no missing or null values on both the edge and also no missing ID for the vertices (at least in the CSV file)

Did you find a solution to the problem?

By fixing the data problems upstream. I could only find them via a tedious debugging procedure.