The file sproxy.cgi was associated with the Discus interface to the spellchecker.net spell checking service, which was implemented in some beta versions and early releases of Discus 3.10 in early 2001. Since this time, spellchecker.net ceased to offer their free spell checking service, and their code was removed from Discus 3.10 and 4.0 as a result.

If you installed Discus while the spellchecker.net mechanism was still supported, you will have the sproxy.cgi file still in your Discus CGI directory. And, since the diagnostics from your new version of Discus have no information about this no-longer-distributed file, an error message will be reported along with the file.

You should simply delete the sproxy.cgi file from your server. This file is no longer used by Discus.