Restore not working - Incompatilha Index Format

Hi. I have a cluster 4.6 and some restores files. I donwloaded one of them and when I try do run locally, I get :

“error”:“UnsupportedFormat: Index: {name: role_1_db_1, ns: admin.system.roles} has incompatible format version: 8”,“file”:“src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp”,“line”:527

I tried with version 4.0, 4.2, 4.6, 5.0 and all setFeatureCompatibilityVersion possibilities and nothing!

The point is, why store a backup if no one can restore it?

cheers