Import CSV-file not working – despite debug

Hello.
I am trying to import a csv-file with listings (CPT:Brautmode) the system keeps on telling me that none of the listings could be imported due to
a) missing title or unvalid CPT
and
b) unvalid address (address,city,region …)

What I have done so far to find the error:
– I have created listings from the front end
– then exported these listings into a csv-file and saved it with Open Office -> UTF 8, German language, comma seperated
– on the basis of this exported csv-file I created the csv-file with all listings to be imported, providing all mandatory data just as provided from the exported csv.
– made sure the csv-file imported has exactly the same structure as the csv-file I had exported before, including all latitude/longitude information in the required format (55.5453453436, 10.45353534)
– installed the wp debugging as recommended in the trouble shooting, however the debug.log comes up with exactly the same information as already provided (see above).

And I just do not see what the problem is, because all address data, title and cpt seem to be correct.

However, when I export the listings created in the front end, save the csv-file as recommended (Open Office, UTF 8, comma seperated …) and try to import exactly this file without making any changes, this also does not work. Again for the reasons above, even though – as far as I can see – all required information and columns are provided.

Any idea, what might be the problem?
Many thanks
Birgit