I picked up a blueprint from the quickbar and received this error.

The mod Blueprint logistics requests (1.0.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event blueprint-request::on_player_cursor_stack_changed (ID 30)
Gui element with name blueprint-request-button already present in the parent element.
stack traceback:
[C]: in function 'add'
blueprint-request/control.lua:28: in function <blueprint-request/control.lua:22>

Uploaded autosave with a blueprint in hand, and got an error

Error while running event blueprint-requeston_player_cursor_stack_changed
(ID 30)
Gui element with name blueprint-request-button already present in the parent
element.
stack traceback:
[C) in function add"
＿blueprint-request＿/controllua:28: in function
＿blueprint-request＿/controlJua:22>

This is caused when you save with a blueprint in your hand, then reload that save, really weird issue I can't find a way to fix it, without just reverting before this happens. Hope the mod author fixes it soon.

Interesting. Thank you for the informing us about the cause. I didn't know what the problem was so I disabled the mod. Now I can re-enable the mod to use it and will keep in mind not to save the game with a BP in hand.

Fixed