Please note that Greenbone isn’t involved into packaging GVM Kali or any other Linux Distribution and your user experience may vary depending on the quality of the third party integration of GVM. The Greenbone Security Manager TRIAL with Greenbone OS 20.08 now available! - Release Announcements (Greenbone Professional Ed) - Greenbone Community Forum could be an alternative, while “TRIAL” is included in the name the GSM TRIAL doesn’t have any time restrictions on it’s usage.
Concerning the error message itself:
I have seen such messages on older GVM 20.08 versions (newer ones have improved the message to be more descriptive) if the report formats used by gvmd are missing / where not correctly migrated from a previous GVM version like GVM-11.
If this is a migrated GVM setup (e.g. a previous OpenVAS / GVM version was installed) please refer to the Kali package documentation if there are any additional steps required for a migration and if the problem persists please create a new issue for the Kali package maintainer at https://bugs.kali.org.
On a fresh installation this problem AFAIK shouldn’t happen because the report formats are not migrated in that case but installed from the GVM_DATA feed. But you still can check if the report formats exists with e.g.:
$ ls <install-prefix>/var/lib/gvm/data-objects/gvmd/20.08/report_formats/
(replace <install-prefix> with the path used by Kali, i guess no install-prefix is used there)
which should return something like e.g.:
anonymous-xml-5057e5cc-b825-11e4-9d0e-28d24461215b.xml itg-77bd6c4a-1f62-11e1-abf0-406186ea4fc5.xml txt-a3810a62-1f62-11e1-9219-406186ea4fc5.xml
csv-results-c1645568-627a-11e3-a660-406186ea4fc5.xml pdf-c402cc3e-b531-11e1-9163-406186ea4fc5.xml xml-a994b278-1f62-11e1-96ac-406186ea4fc5.xml
If that folder doesn’t exist it might be possible that something went wrong during the import of the report formats so you could try to repeat the important steps for GVM 20.08 mentioned here: