For this train reservation is not possiblr via bahn.com only via interrail.eu or at DB or SNCF Ticket Office or Call Center.

getting simmilar result

Interrail.eu has often some problems, you could try to call SNCF or DB. At DB you can collect the reservation at a ticket machine to print them there. Or at the Station. 

@rvdborgt Have this trains only some seats for Interrail users or all seats can be booked with Interrail? 2018 DB could not sell me a seat because all interrail seats were full, but normal tickets was possible...

As you can see in the image I need to get that ticket beacause it’s part of my journey from berlin to barcelona, does this mean that i won’t be able to get this train anymore, or does it mean that i have to get it at the station?

just visit a station or call DB the food thing is they can even reserve the TGV Paris - Barcelona in case of free seats

@ IC/TGV DE->FR: These are coöperative between the 2 and I guess that SNCF puts on its own quota ruling at least for the sector in FRance-and thus also for all overtheborder trips. Though noone will tell you how it really works.

@juano-you have much more chance and pay much less by using local (tiny SWEG dieselset under the wires) Offenburg (connect from KSA0 to Strasbg-then hourly FRench TGV=much less in demand=much higher chance to find seats.

IF you plan to connect into this train at KA: expect heavy delays in train 1 and a missed connection.

Thanks all, I’ve already talked to the Bahn and apparently they will give me a reservation number which I will be able to use to pay for my reservation at any station

Still having trouble with reservations in France, but the call center is already  closed,I’ll try and call tomorrow

I've read some reports in DSO that the 13€ reservations sold by SNCF (and most others) are quota-controlled but the 16€ reservations sold by DB are not. I haven't been able yet to verify this myself.