When a malformed URL is received as a link, using the form of "//site.com/path" with no leading "protocol:", the function htFileExists() will stall for about 30 seconds.
When this URL fails to load normally in THtmlViewer.LoadFromUrl(), the code tries to treat this as a file and converts to the form of "\site.com\path". Calling "ExpandFileName()" converts the slashes. The URL is treated as if it started with "file:" as the protocol.
When FileExists() is called in htFileExists(), the path is treated as a UNC path. Windows tries to locate a machine named "site.com" on the local network and hangs until it times out. This causes the program to freeze for about 30 seconds by default.