"Texture Streaming Pool Over..." Message when not using textures

I am currently working on a GearVR game with 360° equirectangular stereo panoramas as skyboxes.

Of course only one skybox is used at any given time.

But I have noticed that when too many 360° stereo panoramas textures are imported to the project (even if they are never used), the “streaming pool over…” warning message is displayed when playing in the editor.

In that case, the game simply crashes at startup on the GearVR.

What would be the procedure to make sure that the “streaming pool over…” warning message is not displayed, even when many large textures are imported to the project (and thus avoid the game crashing on the GearVR)?