Can't change the start date on projects/Milestones etc.

[Naomi Carey]

Hi - Can anyone advise me as to why I cannot change my start date to be in the past? I've checked I have no dependencies linked, yet I am unable to change the start date of the top project on the gantt. Every time I try it just resets to be in the future again. 

Any advise would be greatly appreciated, 

Thanks  

[Dave Mathijs]

Hi @Naomi Fensome which third-party app are you using since you mention "gantt" in Confluence?