4.12.1 Crash when trying to compile (DEMO PROJECT)

As soon as 4.12.1 showed up, this started happening. Another user has similar issue, probably it’s related, HERE.

I’ve reproduced this in a very simple blueprint setup, here is a simple repro project:
DEMO REPRO PROJECT

Repro steps:

  1. Create empty Actor blueprint, ‘A’ & ‘B’.
  2. Leave ‘B’ empty, but in ‘A’ create variables: array of ‘B’ actors and array of Vectors (or Rotators)
  3. In Event Graph (or Construction script, no matter where) of blueprint A place these two variables… And for array of ‘B’ take its Length (or do any other operation on it) and for array of Vectors, make a ForEachLoop with it.
  4. Compile blueprint ‘A’ and then try to compile blueprint ‘B’, now it will crash.

This prevents me from updating my Marketplace tool for 4.12, so I would be really grateful if this could be fixed soon… Thanks!

Hello,

I have reproduced this crash and entered a bug report, UE-31740. Thank you for your report.

Have a great day

Also experiencing the same problem after upgrading to 4.12.1

Also experiencing this, I have a feeling there are a few more compiling related crashes.

On the main 4.12 thread, Stephen Ellis refers to this thread and says a hotfix is being worked on ASAP (just to add to the info pile here)

We have already fixed this issue internally. If you are a source code developer using GitHub, you can grab and integrate the fix here: https://github.com/EpicGames/UnrealEngine/commit/38457aec8e69e7423b6f606dc9ac22a8e63e2635 (you need to be signed into your GitHub account). If you use the binary release from the launcher instead, then we will be releasing a new hotfix for this issue very soon this week.

Yep. Cannot do anything with For Each Loop. Waiting for hotfix!

Also experiencing the same problem after upgrading to 4.12.1. "The trick is to save the widget blueprint before hitting compile.

You still crash to desktop but on loading the editor again you’ll find the widget blueprint has compiled and you can now test your changes."

Same workaround, it’s annoing but i don’t have to redone stuff everytime.

now crashing when compiling a blueprint function library in 4.12.1 =(

Hoping to reopen this issue, i have been experiencing this same bug but in 4.12.5 any ideas how it could be rearing it’s head again?

Hey Twelvecaliber,

I went ahead and tested the issue with the repro steps listed here and it did not occur: Unreal Engine Issues and Bug Tracker (UE-31740)

What steps are you following when you are experiencing the crash?