Did you follow the link in the error message you provided?
There they write
MISSING_FILE
- The file cannot be found but has been specified within
signature.json
. Either a required file has been left out, orsignature.json
needs to be edited.
So just extract the two files from your original zip or tarball to the owncloud installation directory.
Use the forum’s search functionality! This would have shown this thread: Solved - Missing files when migrating from from 10.0.10.4 to 10.2.1.4
Edit: out of curiosity: where did you get your owncloud archive from?