I have noticed a problem with FTP. I think it has something to do with the connection being closed due to inactivity.
When it happens, the only way to get back on the FTP is to close WeBuilder. (The "Recover from crash" feature doesn't work in this case.)
Here's what happens:
Clicking on FTP connection gives requester: "FTP Error: Connection Closed Gracefully".
Then when I click "OK", another requester pops up: "FTP Error: Already connected."
And then WeBuilder crashes.
I'll try to send a bugreport from within WeBuilder next time it happens. (If I can get it to trigger the stupid Windows 10 Mail client)