Bug in 4.14 when streaming landscapes with foliage

I’ve made a world map that streams levels based on distance using the world composition features, and recently update to 4.14 to use the forward rendering features. I have a landscape grass type applied to a landscape material layer that I paint to create lush dense grass. Honestly, first off, it looks great with the new forward rendering, the amount of grass I’m able to place while maintaining high frame rates is unbelievable. The only problem I’m having is a pesky error message in the log that is compounding, and causing a performance hit during longer sessions, the log reads;

PIE:Warning: Warning Mobility of LandscapeStreamingProxy_0 : HierarchicalInstancedStaticMeshComponent_154 has to be ‘Movable’ if you’d like to move.

and it repeats that going through thousands of iterations.

I know that I’m probably mashing up features that haven’t been optimized for each other yet, but I wanted to place a bug report about this in case it proves helpful to anyone else.

Hi Aaron,

Thanks for the report! I’ve submitted a ticket for this to be investigated. You can track the status here: Unreal Engine Issues and Bug Tracker (UE-38694)


I’m having a similar issue in 4.14 but my error matches this answerhub thread instead:

…in that it’s simply warning on Landscape_0 - so I assume this is a problem with grasstype foliage on all landscapes, not just streaming proxies?

My warning is:
Warning Mobility of Landscape_0 : HierarchicalInstancedStaticMeshComponent_0 has to be ‘Movable’ if you’d like to move.

If I remove the grasstype from the landscape material, the warnings go away.

Right, not just happening on streaming proxies. Happens with landscape grasstype applied to any landscape on initial load of the level the log will be spammed with the number of proxies that grasstype is applied to or the number of components for the landscape that it’s applied to. If these are unloaded and loaded back in they will spam the log again and again as they come and go. If the landscape is never unloaded it’s only hitting the log once that I saw. This is all mentioned in the ticket posted above.

Thanks. Sorry - in my defence I probably didn’t read the ticket properly.

Having this issue too, does it actually affect anything though?