"Key Structure" reroute nodes cause compilation problems

reroute nodes of “Key Structure” cause the blueprint to get “dirty; need compilation” right after you compile it. no matter how many times.


i have noticed that only with Jesus Christ help after 3 weeks of compilation hell (by rolling back with other purpose).

this was the solution…


extremely stealthy and annoying bug.

Hello Arty-McLabin,

I was able to reproduce this issue on our end. I have written up a report and I have submitted it to the developers for further consideration. I have provided a link to the public tracker. Please feel free to use the link provided for future updates.

Link: Unreal Engine Issues and Bug Tracker (UE-46223)

Make it a great day


This bug is still there.

Having a reroute node on a Key Structure wire prevents the Blueprint to compile. Once removed, I have to compile twice in a row to finally get my blueprint good to go.

Tested in 4.19.1.

I run into this last week too when comparing mouse buttons even though no reroute pins were used.

@Rudy, shall i resubmit that case via the new form? Unreal Engine Bug Submission Form - Formstack


I ran a few quick tests and I was unable to reproduce this issue on our end. We’ve recently made a switch to a new bug reporting method using a more structured form. Please visit the link below for more details and report the issue using the new Bug Submission Form. Feel free to continue to use this thread for community discussion around the issue.


Just tested again in an empty project. This is a screenshot from the level blueprint.

Plug in the disconnected wire and compiling is going to fail.

I reported the issue a while ago, but nobody created an entry for this bug.


Hello All,

I was able to reproduce this in 4.19 (Rudy was using original repro steps that did not involve == node)

However, I was unable to reproduce in 4.20!

I’ll be getting notifications on this thread - so let me know here if there are still any issues after checking for yourself in the 4.20 preview (when it launches)