The new packer version 1.7.3 doesn't support the export_opts option set to iso. So I deleted that option in all json files and the software worked after that.
Reference: https://www.packer.io/docs/builders/virtualbox/iso Please find export_opts in this webpage. I couldn't find any --iso option.
Fix #12. Packer failed to install ( Unsupported export option --iso )
The new packer version 1.7.3 doesn't support the export_opts option set to iso. So I deleted that option in all json files and the software worked after that. Reference: https://www.packer.io/docs/builders/virtualbox/iso Please find export_opts in this webpage. I couldn't find any --iso option.