JobItemForm don't check if hasTranslator and fail when Save.
This happens if you are in "admin/structure/types/manage/article/translate" and you request translation and close without Submitting. Then you go again to "admin/structure/types/manage/article/translate" click "In progress" and try to Save. You will get an Exception.
Add validation in JobItemForm to check if hasTranslator when saving.
And maybe redirect to the JobForm if the job do not have translator when building the form.
create a patch, review and commit
User interface changes