Debugging Script, Type Error when checking for Null

I have a script that works well enough on one game, but breaks once imported to another. Here is the snippet in question    debugVariable = function(target_var) {     sendChat('',JSON.stringify (target_var)); }, ......         nl.get('notes', function(n){                     debugVariable('hhh2');                     debugVariable(n);             if(!_.isNull(n)){ This basically looks up the content of a Journal entry and is nearly copy pasted from another script called JournalLog. The fourth/fifth line sets 'n' to the contents of the log correctly and is outputted into the chat on line sixth/seventh. The final line, for some unknown reason, throws a fit and dies TypeError: Cannot read property '0' of null TypeError: Cannot read property '0' of null at incrementDate (apiscript.js:3590:56) at Timeout._onTimeout (apiscript.js:3514:30) at listOnTimeout (internal/timers.js:549:17) at processTimers (internal/timers.js:492:7) I cannot understand for the life of me why this would fail here when it runs fine everywhere else Any ideas on what mistake I am making? Since the error is referencing incrementDate, even though it doesn't make it that far....here is some more of the code }, incrementDate = function(journal_contents,args) {   debugVariable('bla');// Doesn't output ....... }, passTime = function(args) {         nl = getNoteLog();                     debugVariable('hhh1');   // outputs fine         nl.get('notes', function(n){                     debugVariable('hhh2'); //outputs fine                     debugVariable(n); //outputs fine             if(!_.isNull(n)){                     debugVariable('hhh3'); //Doesn't output                 setTimeout(function(){                     debugVariable('hhh4');                     let text=incrementDate(n,args);                     debugVariable(text);                     sendChat('',`/desc ${getDate(text,'short')}`);                     nl.set('notes',text);                 },0);             }         }); },

Can you post all of IncrementDate?  sendChat() is asynchronous, so a failure further in the function could prevent the sendChat from occurring, even if the failure is further along in the code.

.match() on a string returns the special value null when it doesn't find a match.  So this line: var results = journal_contents.match(/.*>It is (\d+) seconds past (\d+):(\d+) (\w+) (\w+) \(\w+\) (\d+).. year (\d+)<\/h1>/i); is failing to match the contents and is returning null .  Then this line is trying to deference index 0 from it:   var remainder = journal_contents.substring(results[0].length); There are a number of ways you might fix that, depending on what you're after.  As of Javascript ES6, there's no problem comparing to null directly, so you could just check and return:   var results = journal_contents.match(/.*>It is (\d+) seconds past (\d+):(\d+) (\w+) (\w+) \(\w+\) (\d+).. year (\d+)<\/h1>/i); if(null === results){ return; } etc.

Nevermind. Thank you I figured it must be that line, but since the debugVariable wasn't outputting I was looking elsewhere