AssetBundle has something strange, build only 1kb size

Unity Engine
1

When I clean the asset bundle export folder, and build asset bundle again, some asset bundle files are unusual, like this:

Bundle Name: a_light_001.bundle
Compressed Size:1.2 kb
Uncompressed usage by category (Percentages based on user generated assets only):
Textures 341.6 kb 98.8%
Meshes 0.0 kb 0.0%
Animations 0.0 kb 0.0%
Sounds 0.0 kb 0.0%
Shaders 0.0 kb 0.0%
Other Assets 0.2 kb 0.1%
Levels 0.0 kb 0.0%
Scripts 0.0 kb 0.0%
Included DLLs 0.0 kb 0.0%
File headers 4.0 kb 1.2%
Total User Assets 345.8 kb 100.0%
Complete build size 345.8 kb
Used Assets and files from the Resources folder, sorted by uncompressed size:
341.6 kb 98.8% Assets/Art/Effects/UI_Texture/a_light_001.tga
0.2 kb 0.1% AssetBundle Object

Bundle Name: m_city.bundle
Compressed Size:1.1 kb
Uncompressed usage by category (Percentages based on user generated assets only):
Textures 0.0 kb 0.0%
Meshes 0.0 kb 0.0%
Animations 0.0 kb 0.0%
Sounds 224.6 kb 98.2%
Shaders 0.0 kb 0.0%
Other Assets 0.2 kb 0.1%
Levels 0.0 kb 0.0%
Scripts 0.0 kb 0.0%
Included DLLs 0.0 kb 0.0%
File headers 4.0 kb 1.7%
Total User Assets 228.8 kb 100.0%
Complete build size 228.8 kb
Used Assets and files from the Resources folder, sorted by uncompressed size:
224.6 kb 98.2% Assets/Main/Sound/Music/m_city.ogg
0.2 kb 0.1% AssetBundle Object

asset bundle is 1.2kb or 1.1kb, but the origin asset file is 341.6kb or 224.6kb, and the asset files is correct.

when I use this asset bundle, It shows “Failed to decompress data for the AssetBundle ‘xxx.bundle’.”

I’m using the Unity2018.3.3f1, whether it is strict mode or not, I have tried.

Has anyone encountered the same thing?

2

when I delete the incorrect asset bundle files, and build asset bundle without clean the folder, it run well

Bundle Name: a_light_001.bundle
Compressed Size:105.6 kb
Uncompressed usage by category (Percentages based on user generated assets only):
Textures 341.6 kb 98.8%
Meshes 0.0 kb 0.0%
Animations 0.0 kb 0.0%
Sounds 0.0 kb 0.0%
Shaders 0.0 kb 0.0%
Other Assets 0.2 kb 0.1%
Levels 0.0 kb 0.0%
Scripts 0.0 kb 0.0%
Included DLLs 0.0 kb 0.0%
File headers 4.0 kb 1.2%
Total User Assets 345.8 kb 100.0%
Complete build size 345.8 kb
Used Assets and files from the Resources folder, sorted by uncompressed size:
341.6 kb 98.8% Assets/Art/Effects/UI_Texture/a_light_001.tga
0.2 kb 0.1% AssetBundle Object

and when I clean the folder and build again, it incorrect again…

I’m confused >_<

3

well, it’s a unity bug and fixed in 2018.3.6f1

4

I just ran into this on 2018.3.0f1. Random AssetBundles were building with 1k size. This was a hard one to pin down since our build logs don’t obviously indicate when a file has failed to build correctly. We also saw the error “Failed to decompress data for the AssetBundle ‘xxx.bundle’.”

About to upgrade to 2018.4.5f2 to see if this fixes it.