Mysterious 'Password Required' dialog on startup

Every time I start KNIME (Analytics Platform 3.2.1, Windows 7 64-bit) I get a 'Password Required' dialog, but there is no site name or address shown after 'Connect to:'.

If I cancel this dialog it doesn't seem to stop anything from working - I can successfully run Install New Software to download and install updates, and I can download and use examples from the examples server.  I haven't created any workflows that involve internet connections, as far as I'm aware.

If I check the Error Log after cancelling this dialog I see the following entries:

Invalid input url:platform:/plugin/org.knime.ext.weka_3.7/icons/weka_splash_24.png

and then three repeats of:

System property http.proxyPort is not set but should be 8080.

System property http.proxyHost is not set but should be (my company's proxy server)

The proxy server settings are correct in KNIME's preferences (General, Network Connections).

This is only an annoyance not a blocking problem but I'd like to find out how to stop it if possible - especially as I'm hoping to introduce colleagues to KNIME. Any suggestions please? I can supply the full details from the error log if that helps.

I am not sure what this could be.

Maybe an open workflow with credentials? Can you attach the password screenshot?

Maybe I recognize where it is coming from.


I'm not aware that I've used any nodes or workflows that need credentials, unless it's one from the examples server.

Do you require a proxy to access the internet? If so, this dialog may come from your proxy that requires authentication. It may also be a 3rd party update site that requires login (update sites are scanned during startup for updates).

I do need a proxy, as mentioned, and have configured it for HTTP and HTTPS in KNIME's General > Network Connections preferences including the required username and password.

I've tried unticking everything in the Available Software Sites preferences and still get the dialog...

Just in case anyone’s interested, since I originally posted this topic I started using px on my computer (which authenticates via Windows with a remote proxy server, then provides a local proxy server that doesn’t need authentication, for clients that don’t support it) and the other day I thought to try configuring KNIME to use the local px proxy instead of the remote one. What do you know, the mysterious dialog no longer appears.