We are having problems with derived flat patterns not updating without their reference models being open, but only on derived parts. I have attached test files (open Top Level Assembly.sldasm to test).

I created an assembly with three identical parts created three ways:

• Derived Part 03.sldprt - Save bodies command and then converted to sheet metal
• Insert to new Part 03.sldprt - Insert to new part and converted to sheet metal (though I’m pretty sure SW is doing nearly identical stuff in the background between this and the last)
• New Part 03 - Create new sheet metal part, no multi-bodies involved.

Reference Part.sldprt drives the geometry. For testing, I just change the width of the opening in Sketch1 of Reference Part.

If you have the Top Level Assy.sldasm open and change values, everybody behaves as expected, as long as you keep the Assembly open.

Here’s what I don’t understand, and the steps I’ve followed which reproduce the issue every time:

1. Open only Top Level Assy
2. Change a dimension in Reference Part (I have been modifying “Opening Width@Sketch1”)
3. Rebuild, save and CLOSE the assembly.
4. Now, if you open all three parts mentioned above WITHOUT OPENING THEIR REFERENCES, here’s what happens:
   1. Derived Part 03 and Insert to New Part 03 both show the correct opening in the “Default” configuration but show the previous opening size in the Flat Pattern configuration. The reason I suspect a bug is unsuppressing the “Flat-Pattern” feature while in the Default configuration, the correct opening shows. Additionally, new Part 03 shows the correct opening size, regardless of configuration.

I am curious if this has to do with our version, or a setting? We're running SW2016 SP3.

Thank you all in advance.