Are 4.6.0 assets not compatible with 4.4.3?

I migrated some assets over from a 4.6.0 project over to a 4.4.3 project which comprised of 6 textures, 6 materials and a static mesh. The assets are visible in windows explorer but do not show up within the 4.4.3 content browser.
All that is visable is the sub-folders that the assets reside in.

Same problem here with 4.6 and 4.5.1

Same problem with 4.11 and 4.10…