It is full like all trains today to Paris. This route is extremely popular and sells out days if not weeks in advance. The best option to book that rout would've been to call SNCF. Usually this train is also available on interrail.eu but not always due to bugs...

My alternatives :

- R Barcelona-Sants - Cerbère 11:16 - 13:56

- TER Cerbère - Montpellier St-Roch 14:26 - 17:09

- TGV Montpellier St-Roch - Paris Gare de Lyon 17:51 - 21:18 46€ 1st class (seat + upgrade)

Option 2 :

- TER to Montpellier or Nîmes and 1h break

- TER Montpellier/Nîmes - Nîmes Pont du Gard 18:14/18:50 - 18:57

- TGV Nîmes Pont du Gard - Paris Gare de Lyon 19:14 - 22:08 20€ 2nd class

I'll try to see if it's possible to make it to Paris tonight, might be complicated…

To get that 1st class upgrade either you call SNCF (no fee) or use that link (4€ per order) : 

Yeah I heard that too. Unfortunately I saw there was still one ticket available this morning but I couldn’t book the reservation here in the station because they said they couldn’t book for french trains here. Maybe I can take a normal train to a french station and get a high-speed train to Paris from there? 

Ok so I need to reserve the TGV from nimes?

I could buy this one?

Yes you can. Much cheaper than the upgrade I was mentioning above to only arrive 50 min earlier :)

EDIT : You'll be able to have a 1h break in either Montpellier or Nîmes so that's nice. Enjoy the journey along the coast !

Btw if you need to get back to the Netherlands  soon, Thalys will probably be sold out (passholder quota) but you can take a TGV to Lille and then travel via Antwerp. Do not hesitate for questions.

The ticket you were mentioning for Barcelona - Paris was maybe a 1st class one.

Yes. You think dinner is includee at the 1st class option haha? Might be nice as well and 1 hour earlier.

I keep getting this error… althougj there are seats available..

Hi! Thanks for everything. I was able to get this ticket. Other tickets were booked right under my nose .. But indeed a longer stop is also nice to see another place longer . As for the Thalys, interrail isn’t included for Thalys right? Or do you still get a discount? Thanks for letting me now of the alternative option. 

You can buy seat reservations for Thalys with Interrail, but there is a limited number of seats available. 

On popular departures and during high season those sell out weeks, and sometimes months in advance.

The best place to see the availability of passholder seats and make reservations on Thalys is 

https://www.b-europe.com/EN/Booking/Pass#TravelWish

If you don't get any result, press "later trains" and eventually you will find the next available connection. 

If you have a mobile pass you need to generate a Pass Cover Number in order to make the reservation at b-europe. You do that here in the PCN generator:

https://community.eurail.com/news-and-announcements-39/pass-cover-number-generator-is-live-5653