Installing MTA 1.5.6. (as Map Editor) in another folder solves the problem.
https://mirror.multitheftauto.com/mtasa/main/mtasa-1.5.6.exe
I tried to copy Race and Editor resources from 1.5.6 to 1.5.7 and it didnt help.
I have the same problem with testing race maps.
I tried to install race mode of 2015 and the problem didnt disappear. I think this is editor's mistake.