Hi,
I upgraded our project from 4.11.2 to 4.12. I tried both, 4.12.0 first, and 4.12.2 after that, but it even occurs in 4.12.3 (github):
When I try to load a big map (which also included 14 sublevels!), the editor completely freezes. I tried several times, also cleared shader caches and stuff like that, but it simply freezes. I can load any other map of the project but this one.
On other big levels, the shader compiling process takes some time, but at least the editor is responding while compiling. On this level, I see the shader compiler processes working (in the task manager), but the editor no longer responds to anything.
I tried waiting for up to 8 hours! The shader worker processes were no longer working (finished I guess) after that time, but the editor still wouldn’t respond! This also happens after I packaged the game (which succeeds, so it seems to not be a cooking issue), but when trying to load the level in game, the same freeze occurs (just without the shader workers)…
I’m clueless. Everything worked fine in 4.11.2. The log files don’t display error messages, there is also no crash. When I tried to attach a debugger to the editor and forced a break, it stopped at some Ambient Cubemap processing code. We use Ambient Cubemaps a lot, however: We use them in other levels, too (even the same Ambient Cubemaps) and we don’t have an issue there.
Also notable: On my 16 GB RAM machine, 91% RAM were in use while editor freeze, but Unreal Engine (Editor) was displayed as the one that consumed the most memory with ~700 MB (… of 16 GB?.. That seemed strange) and in Visual Studio (breakpoint), it said that the editor process took 13 GB RAM.
What can I do?
P.S.: Since we started PS4 development, too, we need to update to 4.12 as we need to use VS 2015 and SDK 3.50, so going back to 4.11.2 is not really an option here.