I am having the same issue. I offer Digital files that are zipped/compressed and meet the 300mb limit almost all my files average 230mb. Since this pass weekend my customers have been receiving download error messages. I think it's an issue that Squarespace needs to fix. Because I'm able to open the ZIP file of the original on my computer. Once the file is uploaded to Squarespace the ZIP digital file is not able to be opened.
I've attached the message that I'm getting. I've tried on Safari and Google Chrome, had a friend try and the same error is happening.
