When I validate my server files(RSM), my server is working but if i download oxide for it - its giving me a mistake(screenshoot).I delete all plugins from
RSM-server-oxide-plugins, but it didnt solve my problem

Make sure you are using the latest oxide and rust, and both for windows.

That error would imply that you are mixing Rust versions.

how i can "unmix" it? 

Update Rust fully > verify version. Update Oxide using latest > verify version.

Solved