Your console now has no memory of your profile. Your saves are still on the hard drive, but they are currently "orphaned" (they belong to a profile ID that isn't loaded).
Sometimes the error occurs because the license for your profile’s content is trying to sync simultaneously with the profile data. Transferring licenses forces the Xbox 360 to re-authenticate your ownership of digital content, which can resolve handshake errors. xbox 360 your profile was not completely downloaded
The error "Your profile was not completely downloaded" means the handshake between your console and Microsoft’s legacy Xbox Live servers was interrupted. The file was partially written to your storage device, but the verification failed. Consequently, the console refuses to load the profile because the partial file is considered "dirty" or unsafe to use. In Storage → All Devices, search for suspiciously