[JavaScript Error: "Component returned failure code: 0x804b000a (NS_ERROR_MALFORMED_URI) [nsIIOService.newURI]" {file: "chrome://zotero/content/xpcom/storage/webdav.js" line: 205}]
[JavaScript Error: "WebDAV verification failed"]

It looks like you might be entering an invalid URL.

Try again, and if you're still having trouble, provide a Debug ID (different from a Report ID) for a Verify Server attempt that fails.