".uasset' has been saved with empty engine version. The asset will be loaded but may be incompatible."

“.uasset’ has been saved with empty engine version. The asset will be loaded but may be incompatible.”
after upgrade from 4.26 to 4.27, there are many these warnings for the uasset. should i re-open/save all uaaset after upgrade the UE? if it was, is there automatic way to do this?

This usually happens when you create an asset in a source build of the engine and then load it in a launcher build. Is that what you did?


nope, i Created a sample project from Launcher which is UE4.26. then i upgrade the project to UE4.27

Hm. Very strange, then. Normally launcher builds are configured to save the engine version.

no errors while build the project using 4.26. but after upgrade to 4.27, it seems that users have to re-open/save all the .uasset files…and i still did not find any tool or command to to this automatically

You can use the ResavePackages commandlet to automatically re-save all assets.

would you please give me the doc or a full command example? never use that kinda command yet. Thanks

You’d open a cmd window and run a command like

"C:\Program Files\Epic Games\UE_4.27\Engine\Binaries\Win64\UE4Editor-Cmd.exe" "Path\To\YourThing.uproject" -Run=ResavePackages -PackageSubstring=/Game/

Wrote that from memory, so it may be wrong. A proper documentation page doesn’t seem to exist…

OK, Thanks so much!

what does this mean? run this in cmd window is OK, but donot call this cmd from C++ code?

Just means I might have misremembered the command, so you’ll need to experiment a bit

ok, thanks!

For the record, that command is correct. Except you’ll have to change -PackageSubstring=/Game/ to whatever you need to isolate the assets you’re after (eg -PackageSubstring=/YourProjectName/Content/).