How to fix common VuGen recording problems

One of the problems that occurs on occasion when using VuGen, are problems with Internet Explorer when starting a recording of a Web HTTP/HTML protocol script.

These problems can manifest in different ways; for example, a hanging or unresponsive IE window; a windows error message; or a VuGen crash.

I’ll assume that you’ve already tried restarting VuGen, Internet Explorer itself, and even your computer.

The Quick fix

I’m going to jump the gun a bit here, and say that often the quickest way to fix recording issues is to change the “Capture Level”. The three choices offered are; Sockets Level; WinINet Level; or, Both Sockets and WinINet.

By default, Sockets Level should be selected by default. Go ahead and try “WinINet Level”. 9 times of out 10, this will fix the recording issue.

Using either, Sockets or WinINet capture levels, will highly likely result in an identical script; for standard web applications recorded in Internet Explorer.

This “quick fix” is a little deceptive, as it’s no really a fix just a workaround. But it should get you moving forward (most of the time).


So, you’re still reading huh? The capture level trick didn’t work, huh?
Don’t worry; we’re just getting started. :-)

The next step is to ensure you are using the right version of IE. Not every version of IE is compatible with every version of VuGen. I’ve compiled the following chart to help you out:

VuGen 8.1 Yes FP3 with IE7 Patch No No
VuGen 9.1 Yes Yes No No
VuGen 9.5 Yes Yes 9.52 With IE8 Patch No
VuGen 11.0 Yes Yes Yes LR Patch 3

Also note, the LR 8.1 and LR 9.1 is out of support; so they are unlikely to work on a fully patched operating system. It is recommended that you upgraded to a supported version.

Additionally, Internet Explorer 10 is expected to be available later this year; at this stage there is no news regarding LoadRunner support, but based on past experience support will likely arrive in a future release.

Other factors

So, you’re still reading. No worries; I’m not out of ideas yet.

Give the following things a try:

  • Disable all non-essential IE toolbars and extensions.
    This can be done via the Manage Add-ons option in the Tools menu.
  • Disable VuGen thumbnails; In RegEdit, navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Mercury Interactive\LoadRunner\Vugen\Thumbnails and set the value for GenerateThumbs to 0.
    Note, that thumbnail generation commonly causes problems even when IE behaves itself. It’s good to disable it, as thumbnails are rarely needed.
  • Clear your TEMP directories. LoadRunner creates a lot of temporary files; make sure you save your scripts and exit all your applications first.
  • Disable Data Execution Prevention (DEP). Whist I haven’t seen this cause problems for VuGen in recent years, it’s still a very good troubleshooting step. Information about disabling DEP can be easily found using your favourite internet search engine.
  • Disable your Anti-Virus. Anti-Virus software is rarely a good idea on LoadRunner PC; and it can be difficult to disable. Remember to exercise a security mitigation plan when disabling Anti-Virus components.
  • Try using a different administrative user account. Sometimes a user profile may become corrupted and not operative correctly.
  • Try reinstalling LoadRunner and all respective patches.


So you’re still here?

It’s important to understand that whilst LoadRunner is a well-constructed and well-supported product; it does utilise some complicated and highly technical “hooks” to capture traffic from Internet Explorer. Because of this, LoadRunner can be easily affected by low-level system configuration and conflicts; which are difficult to diagnose.

For these situations, it’s possible to use the “Earlier Recording Engine” when recording a Web HTTP/HTML script. To use this, go to “Recording Options > Advanced”. Then check the box, labelled “Record script using earlier recording engine”. Note, that you will need to close your current script and create a new one to invoke this recording option. Note, that IE9 is not supported by this recording engine at this stage.

Do you have any tips for fixing VuGen recording problems? Leave them below in the comments…

UPDATE: For specific recording issues with the AMF Flex or Java-Over-HTTP protocols see the comments below.