From what I understand the problem lies somewhere in how the WebUI pings the server. I think the WebUI is trying to ping the server and is returning an unexpected response which results in the freeze. I would then think there is a problem with the code responsible for the ping. Specifically the line in the log which points out it failed to interpret whether the server is currently up or not.
Deleting the server would only solve the symptom not the underlying problem.
Another thing I have to add is the WebUI worked fine for the first couple of days. I had not modified any files after the first day other than some minor changes to the bpermission plugin.