Problem after upgrade from 9.3.6 to 9.3.(7-8)

Hi,

After upgrade server to version 9.3.7 or 9.3.8 PostgreSQL doesn't start
and complains like below:

Jun 13 23:16:43 test postgres[1970]: [3-1] db=,user= FATAL: could not
access status of transaction 1
Jun 13 23:16:43 test postgres[1970]: [3-2] db=,user= DETAIL: Could not
open file "pg_multixact/offsets/0000": No such file or directory.
Jun 13 23:16:43 test postgres[1966]: [2-1] db=,user= LOG: startup
process (PID 1970) exited with exit code 1

I created this file:
dd if=/dev/zero of=/var/lib/pgsql/data/pg_multixact/offsets/0000 bs=256K
count=1

but... I do not know why it happened and whether this is the right solution?

This cluster was upgraded via pg_upgrade from version 9.2

Best regards

--
Andrzej Zawadzki