java.lang.IllegalArgumentException: "" when carriage return present in ajax render attribute

Question

I have this line of code in my application:

<f:ajax event="click"
                        render="#{ULInvestmentPatternUI.premiumForm}
                     fundstable btnModify btnSave"

The section of code is in a h:commandButton in an .xhtml file. When I run the code locally and click on the button I get this error message showing up in my console in Eclipse :

SEVERE: java.lang.IllegalArgumentException: ""

and the buttons which are supposed to update (become enabled) don't.

I've narrowed down the problem to the line wrapping in the render attribute:

render="#{ULInvestmentPatternUI.premiumForm}
                     fundstable btnModify btnSave"

If this is all on one line (no carriage return between #{ULInvestmentPatternUI.premiumForm} and fundstable) then the SEVERE: java.lang.IllegalArgumentException: "" message is not displayed in the console. The relevent buttons on the page still do not update though.

I'm new to the development team that I am in. All the other developers in the team are using the same code and it is working fine for them. I've checked to make sure that my environment is set up the same as everyone else in the team, and everything seems exactly the same.

Can anyone suggest anything please ?

Thanks, Trish.