Game 1.1.91 linux64. mod 1.1.0.

Screen shot with stack dump and entity counts: https://drive.google.com/file/d/1krpBCaK6o1VOvi8vS6Z9INqidLs-QnB7/view?usp=sharing

I was trying to scale that from full scale to -2, and i see in the screen shot it was the first scale to -1 that crashed.

This print has just 4 entities in it. I scaled and used some other more complex prints OK in the same world before this.

The original print was lost in the crash, but here's a recreation of it:

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

After reloading from the crash, my 2nd and further attempts on the same print seem to work fine. So far the crash has only happened once.

It doesn't smell like an interaction with some other mod. I have at least 20 mods loaded, but many are QoL. I previously tested the scaling with some other modded items like stack combinators. It didn't crash there, it correctly ignored everything i tried.

Good luck. And again congratulations for writing a majority of the very best mods out there. You're the man!

It is a strange error.
The error came from line 219. Yet that item (empty blueprint) was just created the line before (line 214-218 is a single line of command.)
That line will create and place the item at (or near) player character position). I cannot think of how this command can fail. Were you standing in a sea of items when you performed the click? Or were you having some auto item pickers (like Schall Pickup Tower) nearby?
Or a possibility is that the item was immediately taken/removed, right BETWEEN my two consecutive lines of code. Yet this would be a very very rare case. You must be very (un)lucky to encounter that...

If the bug is reproducible (like if the perform the same action, whether in the same save or not), I could investigate into it. I could test if a candidate fix would work or not.
I could possibly add an item existence checking for that, but that does not make too much sense neither. If such sneaky removal can happen between, it can happen after the extra existence checking... Without a reproducible case or save file, I cannot test if such fix is reliable/useful or not.

Thanks for your warm comment here and in another post.

There was no sea of items in the world, no.

And I don't use any automatic picker-uppers.

I do use "nanobots - early bots" in all stages of play, but they were idle at the time.

I also use "connection box" and there were a few nearby, but not involved. I also use "disconnect circuit network", "Nixie Tubes", "Thicker Power Wires", "Wire Shortcuts".

Oh and here's one I use that relates to blueprints: "Blueprint Tools". Maybe it was competing for possession of the new blueprint in order to parse/search it etc..

I could easily have been standing on railway tracks or right up against something, or some other bad position. I don't know.

Also maybe my inventory was full. It was frequently full around that time as I was manually unloading trains to re-test my sophisticated sushi train loader.

Thanks for your information.
Yet I have no idea what could be the cause, so nowhere to try start fixing...

"Blueprint Tools" sounds the nearest one, but if it does not consistently crash every time, then the chance is rather slight...
Standing of tracks should not make any differences, as items can be placed over them like other flat lands.
Even over sea of items should not make any differences neither. Script command surface.create_entity (used in line 214) is "smart" enough to keep finding some space. My experience from developing Schall Remains & Pickup was that the command would keep looking up to very far away from the designated position. When it was located in sea of items, the command would take a longer time, but will eventually place it successfully somewhere. I have not heard of any cases where placing "item-on-ground" would fail. Overall, it is highly unlikely the cause.

Full inventory should not be a cause neither. Insertion into inventory is done at a much later time (line 261).
If inventory was full, it would just perform no action, as if user never clicked that button before.

I do use Schall Remains & Pickup, with the default settings. But I've never seen it automatically try to pick up anything, so that seems unrelated.

I'll post back here if it ever happens again. Thanks very much for checking into it.

Schall Remains & Pickup & Schall Pickup Tower are the two mods that have interactions with items on ground. Former one is purely manual (through hotkey) and later one is purely automatic. Your observation is true.
I pointed it out, just to explain I have many experimentation with script command surface.create_entity, which should work even in sea of items.

Yeah, if you unluckily encounter any crashes again, please let me know. Keeping the save file before a crash may help the investigation.