In extremis, if you find yourself having to make changes on the production server that your users are continuously writing and editing content on, you can enclose modifications to templates and macros in the following #IF statement…
#if($user.psoObjectFinder.getJSessionId()=='_____')##
## New code here
#end##
Replace the underscores in the above with the value of the JSESSIONID cookie returned by the following when pasted into the address bar of your web browser after you have logged in to the Content Explorer…
javascript:prompt('',document.cookie);
That way, only you will see the results of the code within the #ID statement. But it won’t prevent it from failing to assemble pages if the code is illegal.