This page convinced me that the free license should work:
https://www.virten.net/2018/05/free-esxi-6-7-how-to-download-and-get-license-keys/
As you recommended I tried to read/install the license in the console.
Does anybody see a hint of a broken license? Is "Localized" correct?
vim-cmd vimsvc/license --set=N****-*****-*****-*****-****K
serial: N****-*****-*****-*****-****K
vmodl key: esx.hypervisor.cpuPackage
name: VMware vSphere 6 Hypervisor
total: 0
used: 0
unit:
Properties:
[diagnostic] = Insufficient number of per cpu package licenses. At least 2 are currently required, but only 1 provided.
[ProductName] = VMware ESX Server
[ProductVersion] = 6.0
[license_not_set] = 1
[feature] = vsmp:8 ("Up to 8-way virtual SMP")
[FileVersion] = 6.5.2.0
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e16-suite-vsom-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e18-robo-c3-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e4-c2-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e2-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e6-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e4-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e8-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e11-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e9-eoem-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e8-eoem-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e7-eoem-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e1-eoem-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e2-eoem-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e21-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e17-suite-vsom-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e14-suite-vcloud5-c1-201006
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e14-suite-vcloud6-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e19-eoem-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e6-sub-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e7-sub-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e13-suite-vcloud5-c1-201006
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e13-suite-vcloud6-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-eval-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e5-sub-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e12-suite-vcloud6-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e12-suite-vcloud5-c1-201006
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e3-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e1-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e7-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e3-c2-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e5-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e9-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e10-c3-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e20-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e5-robo-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e7-robo-c3-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e6-robo-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e15-suite-vsom-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e8-sub-c1-201306
[LicenseFilePath] = /usr/lib/vmware/licenses/site/license-esx-60-e9-sub-c1-201306
[Localized] = <Not supported type for value: 0x1a369c0>
Result: FAILURE