In 4.17 there is a problem with the long time compilation of blueprints. It does not matter whether they are empty or with logic. If there are many copies of this class on the scene, then the compilation will be a long time.
Steps to reproduce the problem:
Create empty project
Create empty blueprint
Place ~100 copies of this blueprint on scene
Press “compile” in this blueprint
Compilation will be a long time (in my case 10-15 sec)
This will depend heavily on the hardware. With 100 actors (they even have some light logic in them), the compile takes around 2-3s on my old 3570k.
Would you mind sharing sharing your specs?
4.17 introduced a Compilation Manager that is On by default, and the patch notes claimed up to 50% compile time reduction. While this improves things for projects created in 4.17+, some projects that transitioned from previous engine version suffered substantially.
Just something to be aware of.
You’re right. I tried to reproduce this in earlier versions (4.16 and 4.15) - the compilation is also a long one. In earlier versions (below 4.15) I did not notice this. I incorrectly estimated the error causing a long compilation in 4.17 (4.17.1). I started my project in hotfix 4.17.2, a long compilation was fixed, and apparently it was called with something else. Thank you.
Oh, it really helped! My friend turned off the compilation manager and the compilation time was as before. Thank you!
Are you aware of any way to fix this? Do I need to make a clean 1.18 project and port my BPs?
There were hot fixes to the Compilation Manager in 4.18.1 (and 4.18.2 as well, I think). edit: scratch that, these were hotfixes for 4.17, my bad!
Consider bumping the original thread:
It seems you’re not the only only still struggling with it. This has to be fixed on Epic’s side.