You need to find trains without mandatory reservation. Do you want to travel from Malmö or Gothenburg?
I just read in other post there are WORKS that weekend along a part of the direct Malm-STo line- (somewhere near Hässleholm)-so maybe the planner cannot handle that.
The only way on UN-RES toget =is quite roundabout-via Blekinge/east coast (Karlstad? Kalmar?) then by tiny local toget (KrÖsa) till some stop where it links into the main line-and use locals till Linköping or so (I have no Svensk map here at hand-so check yourself.
Or check how it answers if you try the outer ends around the works
Thanks! In the end I went to a swedish station and talked with the staff there. It seemed (probably due to the works on the railroads) all non-reservation tickets had already been sold. We had to pay a reservation, but we managed to get to Stockholm and it wasn't that expensive.
Thank you however for your help!