git lfs pull wasn’t enough in my case. I had recently added all of the larger files to lfs, and they’re definitely present in the filesystem, but the tag error persists. Additionally, the tag error appears for maps that I’m not even including in the game (and I don’t have “cool only maps” or “cook everything” checked).
I am indeed loading an asset for an older version in to my project – specifically an asset from the LearningKit_Games folder, which hasn’t been updated for Unreal Engine 5.6.x yet.
One thing I noticed: The uasset files in question all start with a giant blob of null bytes*. I guess they’re probably corrupted, somehow. I had imported the files using Unreal Engine drag and drop and I see that the files that came from Fab also have the null issue.
^ This is the same issue. The fix is pretty awful, just delete the file, but what’re ya gonna do.
\* Just noticed: The error isn’t limited to files that start with null bytes, unfortunately. However, it does appear that you can detect the bad files from the command line:
$ find . -name \*.uasset -exec file {} \; | grep -v 'Unreal Engine'
./MaterialLibrary/Static/T_EnvTile_MetalGalvanized_BC.uasset: data
I don’t know how to do this on Windows. It might not be possible.