Flash archive ERROR: Archive found, but is not a valid Flash archive

Just recently I was doing another Solaris 10 server installation using Flash archive. This time I encountered the following error:

ERROR: Archive found, but is not a valid Flash archive

I was a bit surprised because I did so many flar installations ... . Anyway little Googling a found out where problem is - I have to remove file

/var/sadm/system/admin/.platform

The above file remembers what platform (sun4u, sun4v, etc) is this flash file prepared for and it turned out that the new servers platform is not included in this file. Removing it and then recreating the archive repairs this error:

mv /var/sadm/system/admin/.platform /var/sadm/system/admin/.platform.old

More detailed description at Sunsolve.