1) If previous save file had a chest size limiter set - will drop out of game with error (sry, didn't write it down)
2) Notes from previous game didn't disappear. But if one tries to Alt+W on them - will drop out of game with error (sry, didn't write it down)
3) When trying to copy an entity that seems to have had note on it or maybe note near it or interacting with something that had a note (can't figure out yet) - { Error running event: Picker Extended:: on_robot_built_entity(ID14) PickerExtended/scripts/notes.lua:446: attempt to index local 'note' (a nil value) }. Scratch that. When placing anything near some specific spot in a wolrd (inside factorissimo mk1 building in my case) - it throws that error anyway.
As per expected - when starting save with mod disabled removed all the notes from the world - and fixed the above,
And of course when mod is loaded back all's fine.
I love picker family mods. Thank you for ur hard work on constantly improving them and maknig them life better!

Yeah, the way that notes were stored was changed. It's an unfortunate fact, but does get mentioned in the changelog. Glad you found a solution.

I might revert this until I come up with a better way. because I don't remember why I made the change.....

@netoen Do you have a save from before upgrading I can use to test with?

This one has to be before the mod update:
https://drive.google.com/open?id=1rsFG9jviUiQ5lpnl0fRy5jOKubBC-5jg

One more when trying to open power armor's inventory: Error while running event color-picker16::on_tick (ID 0)
LuaEquipmentGrid doesn't contain key type.
stack traceback: color-picker16/control.lua:1148: in function <color-picker16/control.lua:1136>
I bet it's from filter part of mod. It was throwing errors all over in 3.0.3
Edit: my bad, it's color-picker mod which, I believe, is also yours.
Not sure about error though, because I haven't had it installed before updating to 3.0.4 of picker extended.

Yeah if it's showing the mod name, it's that mod.

color-picker is not mine

I did add some additional sanity checks around notes. It shouldn't crash, it might print an error, existing notes still possibly an issue.