There are few options when there is a need to attach a file to a ticket at any size (tested up to 512MB).
Attach a file to an existing ticket
Open the ticket from the support portal.
Click on “Add a comment” to start a new comment.
Drag and drop the file into the comment field.
Save the comment.
Attach a file to a new ticket
Click on “Browse” inside the attachments field.
Select a file and click “Open.”