You have to resave your assets to ensure they are saved with your current engine version. You should never use the master branch for active development. Use the release branch or the dedicated branches for each stable version.
To execute a resave you can just run the following commandlet:
start /wait Engine\Binaries\Win64\UE4Editor.exe <path/to/uprojectfile> -run=resavepackages
The commandlet has some arguments that you can use to control the min and max version numbers among others:
- -MINVER=
- -MAXVER=
- SKIPMAPS
- MAPSONLY
- PACKAGE=
- PACKAGEFOLDER=
For all other switches just check the current engine source, there might be more to see ^^