Hi Kevin,
Not sure if you solved this, but Im pretty positive that reason is because you did not copy over upgrade tools from R80.20 version over to R80 and then ran the pre upgrade verifier. So, what I did was found the tools online (just search for R80.20 upgrade tools, its on CP site) and once you copy them over to R80 device (you can simply give them full permission and move them over to $FWDIR/bin/upgrade_tools?R80.20_tools and then execute below command:
./pre_upgrade_verifier -p $FWDIR -c R80 -t R80.20
Im 100% sure it will work.
In case it does not, let me know and Im happy to help you. Just as a reference, below is file content I received when running a tool on R77.30 vm box (file is called pre_upgrade_verification_report.txt
Content (not that this matters to you personally, but just to give you an idea :))
================================
Action items before upgrade:
================================
Warnings: It is recommended to resolve the following problems.
==============================================================
Title: Legacy Default Profiles are not supported
-----
* Description: The Database has Legacy Default Profiles.
They will be deleted:
Endpoint_Full_Access,
Endpoint_Helpdesk,
Endpoint_ReadOnly,
Endpoint_RemoteHelpAndMediaRecovery
Information:
============
Title: LTE Services are not supported yet
-----
* Description: Database contains LTE services that are not yet supported in R80.30
These LTE services will be deleted during the upgrade to R80.30:
Unsupported LTE services are:
gtp_v2_default
gtp_mm_v2_default
gtp_additional_v2_default