I am working on a custom model to retrieve data from purchase orders, involving a total of four collections. These purchase orders are supplied to me by someone else for incorporation into the collections. However, I face an issue with poor-quality files that must be removed from the collection. When I try to remove the collection I get the following error:

Also, trying to delete the files one by one doesn't work. It's like the system just ignores the command.
Does anyone know how to solve this problem or have a workaround? I have tried using different browsers and moving the poor-quality files in another collection and then delete it.
Thanks in advance for any help!