I would almost always run the export and import like this:
$FWDIR/scripts/migrate_server export -v R81.20 -ivw /path/filename.tgz
$FWDIR/scripts/migrate_server import -v R81.20 -ivw /path/filename.tgz
-ivw Will ignore warnings. Most of the time the warnings are for stuff that doesn't really matter, and it's really annoying to have it cancel the entire process just because of some non-important warnings.
Could you show the complete command you ran for both the export and import? Just to verify if you are running it correctly. You can also do a $FWDIR/scripts/migrate_server verify -v R81.20 on the existing management server before hand to get a full report before doing any actual export.
On the new management server, it's important to make sure you already have the correct IP addressing, routing, hostname and DNS configured before starting the import. Ideally you should make it so it can communicate with updates.checkpoint.com for it to automatically update the migrate_server script to the latest version, or update it manually from sk135172:
https://support.checkpoint.com/results/sk/sk135172
I will normally install the latest recommended JHF before doing the import, just to have all latest bugfixes installed.
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