Support Can’t delete .marginbackupall files


I have backed up my data from MarginNote on my iPad. This has created large (50GB) files with the extension “.marginbackupall”. When I try to delete them, I get an error stating “The operation can’t be completed. Couldn’t communicate with a helper application”.

I contacted Apple for some help with this. They were also unable to get the files deleted. They said that the file that is being deleted is trying to contact the application that created it, but is unable to do so. I have MarginNote installed on my iPad and it is working fine.

Could you please help with the deletion of these files? I have three of these 50GB files and they are taking up a lot of space on my iPad.
Many thanks!