file-format
The file is not a readable GnuCash XML book or journal.
Cause. The file does not parse as a GnuCash 2.x-or-later XML book (plain or gzipped), as an SQLite book, or, for
book.replayJournal, as a GnuCash .log journal. GnuCash version 1 files are in this group too.
Fix. Check that you named the right file. Open a very old file in GnuCash and save it again, which upgrades it.
A file damaged by a failed copy needs its backup (<book>.<timestamp>.gnucash).
Code: 1009 · Name: file-format