Where is ExternalId for a File in 6?

I used the ExternalId for Images to check if that images old physical path existed, cause we uploaded many images with the same names that were different. But now I cant seem to find it.

Litium version: 6.1.1

The file field ExternalId that was avaliable in MediaArchive before version 6 is migrated into the Id-field during upgrade to version 6.

@Cissi Please, report this as an bug.

Expected behaviour above does not work, issue is reported as bug Login