Migrate from 4.13 to 4.12 doesn't work

Is it possible to migrate from upper version of UE to lower?
For me it doesn’t work…
Any idea?

As far as I am aware, there is no backwards compatibility between engine versions.

How do you migrate? Literally selecting ‘migrate’ from the content explorer?
Are you using any functionality introduced by 4.13?

And out of curiosity, why the downgrade? Engine issues? Why not wait till the eventual release of a patch?

Yes, just simple migrate function… I need to downgrade because of VRworks.

so it looks like it´s finally there… (4.13)

I don’t think you can downgrade. Earlier versions of the editor will not accept content produced or modified by later versions. Also, be aware that release versions of the editor will not accept content from pre-release versions, even if the pre-release is from the same version of the editor.