The mod All Seeing Satellite (0.6.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event
all-seeing-satellite::all-seeing-satellite-toggle-satellite-mode (ID 212)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'set-controller'
...I-seeing-satellite__/scripts/services/player-service.lua:58: in function
'toggle_satellite_mode'
...ng-satellite__/scripts/controllers/player-controller.lua:89: in function
<...ng-satellite__/scripts/controllers/player-controller.lua:21>

I'm in multiplayer mode and I just clicked comma to enter satellite mode and then comma again and I got this error

Hello, and thank you for the report! I am looking into this, of which I think I may know what the issue is and how to potentially prevent it, but given that it's occurring in multiplayer (which I don't have a real means of testing) it may be difficult for me to test and be confident that the issue has actually been addressed.

It also happens in single player too, I just tested it. Pressed comma, then comma again and it did the same thing.

Hmm, that's very strange, as I use that feature daily while playing/developing and have not encountered this issue.

Do you have any other mods present by chance?

Do you encounter this error if you have only space-age (and quality and elevated-rails) and this mod installed (i.e. no other mods present other than this one)?

Also, contextually speaking, what were you doing at the time leading up to using Satellite mode? I ask, as the error seems to be potentially occurring because either the LuaPlayer object or the LuaPlayer's character object (thinking it's this one) are invalid, given the line it's occurring on:

player.set_controller({ type = defines.controllers.character, character = player_data.character_data.character })

Im playing in a modpack, so theres alot of mods that could be interacting with the mod. Ill see if it still happens with just the space-age mods

What is the modpack if you don't mind? I'm curious to try it myself to test and see what happens as well.