Typically, the orders I have received have been less than $1,000, comprising of less than 10 products. I had no problem editing those order (removing out of stock items, etc).
In the past month, I got one order for over $5,000 (35 products) and another for $4,000 (39 products). When I go to the backend to sales>orders and click the order number, it shows the order, when I click "edit", it asks me "Are you sure?" and when I click "ok" it gives me a blank page.
I am running Magento 18.104.22.168 on shared hosting