HTTP JVM: CLFAD0134E: Exception processing XPage request

On our server we keep getting these "informal" errors.. When I consult the error logs they are equally "informal". Since there is quite a large number of XPages and bases, it is not trivial to start commenting out code etc to know where the error is occurring...
Does anybody know WHY,WHAT and WHERE this error occurs? Getting really frustrated with this now..


HTTP JVM: com.ibm.xsp.webapp.FacesServlet$ExtendedServletException: com.ibm.xsp.exception.EvaluationExceptionEx: Error while executing JavaScript computed expression
HTTP JVM: CLFAD0134E: Exception processing XPage request. For more detailed information, please consult error-log-0.xml located in D:/IBM/Lotus/Domino/data/domino/workspace/logs

FROM error-log-0:
View log here

Debugging tip: insertNotesClientLinks852

Today I got this fairly unknown error when trying to access a document with a XPage.

The runtime has encountered an unexpected error.

Error source
Page Name:/myXpage.xsp


Exception

java.lang.StringIndexOutOfBoundsException
java.lang.String.substring(String.java:1092)
com.ibm.xsp.model.domino.wrapped.DominoRichTextItem.insertNotesClientLinks852(DominoRichTextItem.java:387)

After doing a quick search on google I found a post on the IBM forums claiming this had to do with bad HTML markup within a Rich Text field.

Unfortunately this particular Document had tons of HTML, so it took some time narrowing it down. After some 30 mins I discovered the error was caused by a anchor tag where the href attribute was missing a " at the start...

Anyways.. problem solved!

Debugging tip:Error while executing JavaScript action expression

Occationally we stumble upon some "weird" errors on our xpages. Below is one such error:

Runtime Error

Error source

Page Name:/someXPage.xsp

Exception

Error while executing JavaScript action expression
Script interpreter error, line=385, col=20: 'someJavaScriptMethod()' is undefined and cannot be accessed as an array
at [/someJavaScriptFile.js].methodOne()
at [/someJavaScriptFile.js].methodTwo()
at [/someJavaScriptFile.js].methodThree()

In this specific example it is indeed possible to access the method as an array. The clue here is someJavaScriptMethod(), with no parameters. In my code, line 385(correctly pointed out), the methodcall has several parameters. When the exception is displayed as this, it usually means that at least one of the input parameters is null. This should narrow your scope when searching for the error!

Happy debugging!