In Web Learn under the File menu is an option named "Execution Log...". Its Tool-Tip shows the users "Temp" folder location as the web interface resolves it. If you click that option the file will be opened in the default text editor, if it doesn't exist at that location, it will open up Windows Explorer to that location.
This will show the location of the _Certify_Html_Version3_Log.txt file. Please take a screenshot like the above and send us the screenshot along with the file _Certify_Html_Version3_Log.txt file (once it has been located using the method above). If you still cannot locate the file, please send us just the screenshot of the Weblearn Execution log ... tool tip (as shown above) from the Citrix server.