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:
Create empty Actor blueprint, ‘A’ & ‘B’.
Leave ‘B’ empty, but in ‘A’ create variables: array of ‘B’ actors and array of Vectors (or Rotators)
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.
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!
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.