UMG: 51+GB memory eaten by blueprint compiler.


If a widget blueprint contain hundreds of another widget blueprint instance, the compiling will very very slow:

In my case there is 200+ instances in the main widget blueprint, the sub widget blueprint only have a button widget in it, 50 minutes passed still Not responding:


Hi alonezhby,

Please post this to the answerhub in the bug reports section at so we can better assist you. You can find guidelines for reporting a bug at this page:

Investigating - I think I’ve got a partial fix that will at least not make it take 50 minutes, more like < 10 seconds.