There is a lot ifs in the template and it sometimes fails for tasks with wrong parameteres or plugins which don't have correctly installed argument parsing.
PR #3455
Metadata Update from @tkopecek: - Custom field Size adjusted to None
Metadata Update from @tkopecek: - Issue tagged with: testing-ready
Metadata Update from @relias-redhat: - Issue tagged with: testing-done
Commit 924ad6f5 fixes this issue
Commit 589e49a6 relates to this ticket
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/koji/koji/issues/3454
Please continue any further discussion there.