Is It Possible to Downgrade Your .kmsync File?

I have 3 mac use km version 9 currently.
I made a mistake, upgrade one of my there mac`s km to version 10 (current use version 9), then I think my
.kmsync file got upgrade too. it automatatily sync to all my mac. then I get

"Failed to start syncing macros."
The attempt to start syncing the macros failed (shared file is from a newer version).

so is there anyway to get back my kmsync to work again?

Find a solution: export all your maco in other km, then import back to other mac, finally make a new sync file