Pumpkin problem

Hi all, I recently harvested a few pumpkins that were getting rather large. I cut 2 open today and whilst the flesh looks fine the centre of the pumpkin is green.. any idea what the issue is? Thanks

Thanks Lesley, you are always so helpful! Do you think it's safe to eat the flesh? I was planning on making pumpkin pie! Thanks again

I've had winter squash do that but it is normally next May when the seeds decide they are going to start growing !
The flesh was still good to eat !