Whenever I attempt to move an item that is not assigned to me to "In Progress" from "TO DO", I receive the message "Sorry! Action denied. Your JIRA workflow forbids this move" in a pop-up. I am a member of the Administrators group for both jira and the project.
I'm sure I'm missing something simple, but I just can not find the appropriate permission.
If you are a Project administrator you should check if the Auto-assign setting is checked in the context.
If it is checked and still have the error look at the Task Board configuration and your JIRA statuses-columns mapping.
If not and you want to be it that way, you might have a condition in your workflow that stipulates "Assignee only". Turn it off and you should be able to drag your cards now.
If you are not a Project Admin then it can only be your JIRA statuses-columns mapping.