we are using (more-or-less) happily LR for more than a year. Recently, our UI engineers have upgraded the Prototype library from 1.5.0 version to 1.5.1 (see http://www.prototypejs.org/) and since then we face problems with replaying scripts on our web application in LR.

Even if we record a new script in LR, LR is not able to replay it.
The problems LR reports are always very similar, something like this:
RegisterNewUsers.c(144): Warning -26295: JavaScript error in line 1486: TypeError: $(element).getDimensions is not a function [MsgId: MWAR-26295]

Where RegisterNewUsers.c(144) is the line in LR script that can not be replayed correctly and 'JavaScript error in line 1486' is the line from prototype.js:

1485: getHeight: function(element) {
1486: return $(element).getDimensions().height;
1487: },

As far as I know, the method 'getDimensions()' is being added dynamically on all elements when loading the page. The parameter 'element' is an element id and the function $ returns the element that has this id.

The same problem appears similarly in other scripts, like this one:

Action.c(7): Warning -26295: JavaScript error in line 713: TypeError: $(e).getElementsByClassName is not a function [MsgId: MWAR-26295]

The only change was in upgrading to the new prototype.js version (dynamic adding of methods was there before and worked fine).

Has anyone encountered similar problem or does anyone know how to solve this?

1. What version of LoadRunner (LR) or PerformanceCenter (PC) are you using? (specify which LR or PC)
2. What is the protocol you are recording?
Web (Click and Script)
3. If HTML - are you using HTML-Advanced with URLs or,
4. URL mode with Concurrent groups, or
5. URL mode without Concurrent groups?
6. Which LoadRunner/PerformanceCenter feature or service packs are you using?
6. Feature Pack 4 (LR81FP4.exe LR81FP4P187.exe) and all previous
7. What kind of LoadRunner license do you have - Subscription, Perpetual, Virtual User days, or Evaluation? Permanent
8. If subscription, is subscription current or expired?
9. What platform(s) and Operating Systems? Include version and service packs.
Windows Server 2003 with Service Pack 1 (or Windows XP)
10. If you have filed a service request with HP/Mercury, what have they told you at this point with respect to your issue?