I am running a test to upgrade our splunk server from 4.3.2 to 5.....in my testbed environment which is set up with a clone of our live server, I have run the installation and upgraded to 5 but the splunkweb services fail to start. In the splunkweb log file I see an error where the server is looking for certain directories in the windows app, so I have to rename the directories from 'TA_Windows_FTR' to 'Windows_FTR' and 'TA_Windows_IFrame' to 'Windows_IFrame' to get the services started. If I log in to splunk and open the windows app (running latest version) I get the error in the title of this post. Any ideas?
Underneath the Windows application, you should see an 'appserver' subdirectory, and under that, 'modules'. Additional UI modules shipped with the application live in this subdirectory. The Windows_FTR module in particular is trying to ensure that you don't simultaneously have Splunk_TA_windows or TA_windows combined with the main Windows app. In some versions, it also warns you if you're running your Splunk server on Unix, which is all too common in mixed-OS environments.
At any rate, it's possible that the module isn't there for some reason (and a reinstall of the app should fix it), or one of the files for the module is missing.