This appears to be a duplicate of this item:

https://community.intersystems.com/post/csp-erro-upgrade-cache-161

The solution for how to lookup these error macros by wrapping them in $$$ERRORCODE is the correct approach. An alternative for the one error page you are having problems with is to manually include %occErrors.inc include file.

I think we may need some more context of what the code looks like and exactly what error message you are getting. We do support $$$CacheError in 2016.1, for example:

Set status=$$$ERROR($$$CacheError,$zerror)

If you are trying to lookup the macro value then use $$$ERRORCODE($$$CacheError), then you can write logic like:

If errorcode=$$$ERRORCODE($$$CacheError) Write "It was a Cache error",!

Try:

<script language="Cache" method="OnPreHTTP" arguments="" returntype="%Boolean"> 
     Set %response.ContentType = "text/xml"
    Quit 1</script><?xml version="1.0" encoding="UTF-8" ?>

As the cr/lf after the </script> will end up in the output we generate as this is part of the HTML output rather than inside the script itself.

The correct way to do this is:

set RunStatus=$System.Status.Error($$$ERRORCODE($$$GeneralError),"DXL Testing Run Error")

So use $$$ERRORCODE which can convert the error code to the number correctly.