In the previous builds for 8.3 I had a functional progress texture that used "_islands-queue-progressbar-fill" as the foreground and background textures. In the new 9.0 release (3.0.0) it gives the following error on loading into the game while having such an aura.

RegionPrototype.lua:897: attempt to call method 'SetAtlas' (a nil value)

I would normally give you a WAGO example, but for obvious reasons I cannot. To replicate the issue try creating a progress texture using "_islands-queue-progressbar-fill" or any other Atlases from AtlasInfo.