When the size of the files exceeds the server configured upload size it gives this message after waiting about 2 minutes. May be it happens after a time out. Not sure.
A user will not wait in this UI for 2 minutes. So it might be better to check the total file size before the upload and if the size exceeds give a message straight away, without trying to upload the files.
spiff doesn't know what the limit is (it's controlled externally), so it's not possible to present an error telling them what the actual limit is up front.
When the size of the files exceeds the server configured upload size it gives this message after waiting about 2 minutes. May be it happens after a time out. Not sure. A user will not wait in this UI for 2 minutes. So it might be better to check the total file size before the upload and if the size exceeds give a message straight away, without trying to upload the files.