Blueprint compile error setting array element in Standalone only

I’ve got an array of this structure that I’ve created for my game:

If I try to edit an element in an array of those structures, like this:

It works totally fine when I run PIE, but when I run standalone I get the following error message in the log:

[2018.01.11-16.40.15:991][  0]LogBlueprint: Warning: [Compiler Obelisk_EnergyCore] The structure cannot be broken using generic 'break' node  Break F_EnergyCoreConnect . Try use specialized 'break' function if available.
[2018.01.11-16.40.15:991][  0]LogBlueprint: Error: [Compiler Obelisk_EnergyCore] The structure  Make F_EnergyCoreConnect  is not a BlueprintType. 
[2018.01.11-16.40.15:993][  0]LogBlueprint: Warning: [Compiler Obelisk_EnergyCore] [0052.22] Compile of Obelisk_EnergyCore failed. 1 Fatal Issue(s) 1 Warning(s) [in 15 ms] (/Game/Props/Obelisk/Obelisk_EnergyCore.Obelisk_EnergyCore)

The actor just is “gone” (invisible, no collision) in Standalone, but I can still reference it in script. It’s a gnarly issue that fails relatively silently. To make things even more complicated, I can place this actor in a brand new level and I don’t have any issues. There must be some corrupt data/links in the level that’s failing, so I’m not hopeful this will be reproduceable :confused:

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Thanks

I can confirm the “Make structure” node is the culprit. Same goes for the “Set members in structure” node.
I’m running 4.18.2 (haven’t updated to 4.18.3 since 4.19 is due soon).

This is happening to me too in 4.21.2 - blueprints compile fine in the editor but fail to compile when launching standalone. As Ryan says, the game still runs but things just don’t work, so it’s a silent’ish failure.

Posting this as an “answer” even though it’s still a workaround really, but it seems like the problem occurs with structs that contain a variable that is a non-native object class.

I had a three different structs that were failing to compile make/break nodes and all of them had a custom actor variable in them. Instead, I changed those variables to instead be just “Actor” type, then used a cast/interface instead when I needed to do things with those actors. The compile failure in standalone went away.

I am working on a game that has been in production for nearly 2 years now. After I work on it for a few months and we’re ready to deploy a new update, I always, always get random structs to behave in some problematic manner on Standalone or when packaging.
I usually get the “Unknown struct” issue with some random structs, but this time it was the issue you mentioned. I tried the same fix I always do, open the struct, resave it (sometimes even add a variable, remove it, resave), then I go to the mentioned problematic nodes in blueprint and I refresh the nodes, then resave/compile the BP. And that usually does it and it has for me.

Hopefully it’ll work for you.