Another STS PITA

So here's another problem that took ages to sort out. If the XSD you are using in your project is referencing other XSDs on a server and in your network connection settings you have not bypassed the proxy for that server thn instead of STS informing you of this it does this instead (for ages):

There is no useful warning message or error or time out message. Although the issue itself was not with STS it is still a big usability fail!