I'm using version 2.37h and I have some trouble with the proxy option. As it seems although I've configured this option in various ways (localhost, 127.0.0.1 ecc.; always port 5865) the proxy requests don't arrive at the proxy. Therefore mp3tag fails to connect. I don't use a username or password to connect to the proxy.
I tried the "Check Update" function as well as the websources to test.
The proxy is used in an intranet and works since years.
Later I'll install an older version to verify if it's a problem of the development version.
Anyone else who experiences these problems?