Bugs Related to Blueprint Compilation Manager

Just send either of us a PM on the forums with the dropbox link when it’s available!

Mr Dan, I have sent the private message, please give it a loook. :slight_smile:

Hello !

I will be starting this post with an ubersmall thanks for the Manager with “the Good” section as it’s a great time saver! Then I am giving all the bugs/problems I have encountered so far.

Know that I can share my own project which is around 120 MB zipped to Epic for investigating the issues, especially the crash I mention below as it can’t be produced in a fresh project as the struct needs to be connected to many big blueprints, which is the case for my project and it’s a good way to analyze the crash.

The Good

  • It definitely reduces the launch-compile time. This is a great addition for big projects.
  • Child Blueprints are not compiled meaninglessly when a Parent Blueprint has changes. Again great for big-parent blueprints that holds all the data, compiling them are much faster.
  • Many bugs are fixed related to false cast errors and whatnot.

The Bad

  • When a Parent BP and a Child BP got edits and needs to be compiled, just compiling Parent BP is no longer enough. We have to open and compile all edited blueprints now. Back then “File” - >“Refresh All Nodes” would make a compile on both Parent and Child Blueprints. It would be great if this new Manager could check if a BP’s children needs to be compiled or not.

The Ugly

  • Engine crashes with an “Out of Memory” crash log if you edit a Struct that is used by many blueprints. Since editing a Struct marks all its BP users as “Needs to be Compiled” after making a change on it, Manager is unable to put BPs in order to compile and attempts to do it all at once. Currently I got 3+ BigParents, their children as 3+ SmallParents as their children and 30+ Child blueprints as those smallparents’ children. I got many structs that are used by ALL of these blueprints and they become marked for compile if I touch a struct and Unreal crashes while compiling.

Solution with Manager on: Go from smallest child BPs and compile them individually, then go to their parents to do the same, then to their parents. Doing it the other way around crashes the Engine.

Solution without Manager: From Project Settings, disable the manager, compile, then enable it back.

Very bad solution: Make the changes, close the Engine, save without compiling and let Launch-Compile do the compiling. This gives struct-variable errors across the project so I wouldn’t suggest doing this.

That’s all for now! Thanks for your time and reading!

1 Like

Hello Achilleon,

Thank you for the information above. If you would like to provide a zipped down copy of your project via dropbox or google drive, I will be happy to take a closer look.

Hello Rudy Q!

I can make a dropbox link but I can’t share it publicly. Mr Dan.OConnor from Unreal Forums requested the same thing aswell so I will be doing that tomorrow.

Meanwhile please let me know if I should send the files to him only or you. If you decide to take the link yourself, please let me know your Unreal Forums nickname, if not I can send them to him. :slight_smile:

Here is the forum link for the thread:
https://forums.unrealengine.com/showthread.php?151898-Blueprint-Compilation-Manager-The-Good-The-Bad-and-the-Ugly

Very well!

Thanks for the information Dan! Hoping the best! :slight_smile:

This crash and a crash when saving a related blueprint after making the modification in your video were fixed by this commit and will be part of the 4.17.1 release.

The ChildActorComponent issues are still being investigated.

How do I turn off the Compilation Manager?