Hello,

I know it's really a dumb question. I want to create a maximum size sandbox park (larger than 128*128). I did the following:
1. copy my sandbox park from the documents/rtc3/parks (this were 2 files .dat and .dat.bak)
2. paste them in the new scenario folder
3. opened the scenario editor in rtc3
4. changed the limits of the parc to 250*250 instead of 128*128
5 ( i could'nt buy the land in the scenario editor)
6. I saved the park.
7. i closed rtc3 and copied the park from the new scenario folder.
8. i paste it again in the parc folder.
9. I started the sandbox park again in sandbox mode

Then i can see the map is much larger but i can't buy the extra land and can't build on that land. The map is bigger but the fences are still on the same place.

You were right on the money up until step 4. After that, rather than buy the land you’ll need to set the land as owned by the park. Open that park in scenario editor again, go to the tabs at the top right and choose the second one that says ‘set park land.’

A little window will display. There are some icons at the top on the right side and some icons down the side on the right side in that window. Select the fourth icon down: ‘click to select land that is owned by the park.’

A tab will display in the lower left with a size dot inside a circle and a number that can be increased or decreased with arrows. Increase this to 50, the maximum. Then zoom out of your park and sweep the red grid all over your park.

Presto. All your land is now owned.