What could go wrong ?

everything !

I mean when you press J to start the jetpack by accident when using the zipline already, or when you purposefully try to start ziplining mid-flight because you were using the jetpack. This will be visually problematic, and when you try to leave the zipline pressing F it will throw an error in both situation.

I will try to report on the discord linked in the jetpack mod description too

Interesting find, it's probably because there's 2 mods competing for control of the player. I'm not sure what can be done about it though without specific compatibility coded in, if anything comes up on discord let me know

I went back to the discord to see and there was an answer "Since the crash is on their (your) side, they will have to fix it. I believe there are custom events in Jetpack that they can subscribe to to handle it better."

I have attempted to contact the person who answered for more information.

i understand it makes little sense to try and use both at the same time, and it's pretty obvious/visible when it occurs which character action is responsible for the error, still i hope something can be done so that other player don't have to reload their auto save when discovering it :)

Hey Kiplacon, I'm not related to the Jetpack mod but here's my PM reply:

Take a look at the jetpack mod's control.lua to see the available remote interface functions. The simplest solution is probably to call the "block_jetpack" function when a character gets on the zipline and "unblock_jetpack" when they get off the zipline. That way the jetpack controls will be disabled and they can't interfere. Allowing starting jetpack while on the zipline would be more complicated and I'm not sure which events could be used to detect it.

Interesting, that makes it pretty easy then

Thank you for the fix !