I got an unrecoverable error, 'No such function: freeplay.get_disable_crashsite'.
This prevented me from playing SeaTorio.

Commenting this from line 39 of control.lua in the SeaTorio mod fixes this issue.
--remote.call("freeplay", "get_disable_crashsite", true)

I was able to start the game and was able to get all of the initial items without issues. (So far. Just starting the game.)
:)

Do you know how I can reproduce this? Are there any other mods you run that changes some startups or adjust the crash-site?

I plan to add my AdvancedStart mod on Onedrive in a few minutes.
I didn't try to start without my mod. I suppose I should try that.

Here is a readonly link to my public Factorio Stuff - Look in the mods folder:
https://1drv.ms/u/s!AmbU9TAVLRYBgc03K3dOzPT00kloSA?e=crAqHQ

You should be able to right click the items and copy or download them.
(Edit: My mod was inspired by an old version of this mod. https://mods.factorio.com/mod/IngosAdvancedStart)

I don't remember why that line even was there, Everything seems to work fine without it. I think I I might remove it, after some testing to be sure.
Thanks for reporting this :)

No problem.
Edit: FYI - I use Factorio\data\base\scenarios\freeplay.lua as a guide to what interfaces are allowed. Specifically the
local freeplay_interface variable contains a list of all the available functions for freeplay.