lysesoft.com

I have suddenly started getting error messages when I try to download files

Download failed
Java.io.IOException:
Illegal sftp packet len: 65545

This happens regardless of the file type, location, or size.
Has anyone else seen this?

Yes, it will be fixed in the next release. It's an issue with the default provider (which is deprecated).
In the mean time, go to Advanced => Expert settings => SSH provider => Secure => Save.

It will fix it.