Android Question Error: , java.net.ProtocolException: Expected ':status' header not present, -1

Hey Community

I have a big problem when trying to download a file from dropbox.

It worked for a long time. Then suddenly i always get this error:
Error: , java.net.ProtocolException: Expected ':status' header not present, -1

Research on Github etc did not help

I am using:
OkHttp v1.02
OkHttpUtils v2.20
Net 1.37

I am starting the request using this Code:

Dim request As OkHttpRequest
request.InitializeGet(URL)
HC.Execute(request, TaskID)

I am very thankful for answers. Best regards