7
I had this problem myself after upgrading the system module. I n my case, I lost my customised main menu.
However, I did have a database backup, so I just looked for the table, with the block data, in there and inserted it back into the new database.
I actually found the table in the backup file, copied and pasted just that section into a new textfile then used PHPMyAdmin to import it into the right XOOPS table.
It worked for me but was a little technical.
みんなちがってみんないい。
XOOPS 2.0.13.2