Using SSJS to debug AMPscript. Will produce text to attempt to determine 500 error on CloudPage.

debugAmpscript.ssjs

// Originally found: https://salesforce.stackexchange.com/questions/271607/createsalesforceobject-ampscript

<script runat="server">
  Platform.Load("Core","1.1.1");
  try{
</script>

%%[ YOUR AMPSCRIPT CODE  ]%%

<script runat="server">
  }catch(e){
    Write(Stringify(e));
  }
</script>