Hey!

For which country and train did you try?

Hey!

I tried it for France (TGV)and Italy 

In that case might be that the train is fully booked or not yet open for bookings (e.g. because of construction works and adapted timetables). Did you check on trenitalia.com and sncf.com if there are still standard tickets available on the connection you want to make a reservation?

In Italy they sell only 50% of the tickets at the moment, so on weekends many connections sell out some days in advance.

Thanks a lot for your answer!

Yes, I checked whether tickets are generally still available or not but it was possible.

For example for Thalys it was also possible to buy tickets but not via interrail.

So I wondered why it didn't work via Interrail...

May I ask on which platform did you try to buy tickets?

In earlier years there were only some contingents available for Interrail for TGV but I think this is not the case anymore.

I tried it with the Interrail App

Or did you mean on which platform I tried to buy standard tickets? 

That was on trenitalia.com sncf.com and thalys.com

Oh ok, with that one I have unfortunately no experience.. if you are not super fixed on one connection I’d try to buy it when you get there In case it is sold out, you should still be able to find an alternative connection (except on Sundays maybe)

Okay, thank you very much! :)

Thalys trains can be reserved via B-europe the booking platform of Belgium rail they have a special pass fare Page for Eurostar and Thalys. On Thalys and Eurostar connections are only limited seats for Railpassuser. Could you share which Route you tried as there are maybe other ways to book or to reach your Destination with different trains :) https://www.b-europe.com/DE/Buchen/Pass#TravelWish

Hey, thank you for your answer!

But I have already made a reservation for the Thalys train via B-europe, that was possible :)