No Error Message for Files that are Too Large

I have a file attachment field on my form. I set a file size of 8mb. To test the form and ensure that large files will not be accepted, I am using a 10mb file. When the file is too large, the form spins while the file is uploading and then returns to itself with all of the fields cleared out. There is no error message. When I use an unaccepted file extension the form shows the correct error. When I use a correct file size with an accepted file extension the form submits as expected.