encountered crash when launching rocket in modded game, tested launcing fish and space platform
Game Version: Experimental 2.1.17
Back to Basics Mod Version: 0.2.1
Problematic Mod Compat: PlanetsLib - V1.26.2
Crash report:

Error while running event AAA-back-to-basics::on_rocket_launched (ID 14)
Index out of bounds.
[C]: in function 'index"
__AAA-back-to-basics/script/rocket-silo.lua:62: in function 'switchSilo'
AAA-back-to-basics/script/rocket-silo.lua:112: in function 'revertToNormal'
AAA-back-to-basics/control.lua:27 in function
<AAA-back-to-basics/control.lua:19>

Mod List:
Base Mod - V2.1.17
Elevated Rails - V2.1.17
Quality - V2.1.17
Recycler - V2.1.17
Space Age - V2.1.17
Back to Basics - V0.2.1
PlanetsLib - V1.26.2

Thanks very much for the detailed report, and for narrowing down the problem for me. This should be fixed in version 0.2.2.

I have not played with modded planets (therefore BTB is completely untested with them), and I did not expect that PlanetsLib would allow you to change the recipe in the Rocket silo (which caused the error).

I'll give the usual disclaimer that Back to Basics is intended for a vanilla-style game, and mods that build on Space Age progression should be expected to break.

As someone who spent 2K hours in 1.0, I love being able to go back to the original tech tree and still play space age, and this mod works wounderfuly for that.
I understand the art of programming, and did my due diligence to figure out what of my apx. 100 mods was causing problems.
I hope to use this mod in all of my future playthroughs, and I wish you luck figuring something out, even if it ends up just being incompatible with PlanetsLib.