Yesterday my Android client stopped uploading files, issuing “server not found” messages. However, my server is up and running all right. I restarted the phone, but it did not help. I can connect to my server from the phone (using the browser, using a network analyzer app), so it does not seem to be a phone-related issue (with DNS resolution, for example).
This setup used to work for several years, now it’s boken, what could be going on?