Could you, please, provide more information:
We're in 6.1.379.0.
I can't even find the EPiTrace interface and the boxes related to it also gives errors so I'm gonna go with "No, it doesn't work." :)
Yes, they do.
It looks to be correct. /EPiTrace/Handlers/TrackerHandler.ashx?pageId=21001
Do you think it needs a re-install? Is it "safe" to do so?
EPiTrace is the old name for Live Monitor. You should have a "Live Monitor" menu item under the CMS menu item in the global menu.
One possible reason for having those 404 is that TrackerHandler.ashx is not registered in the web.config. Check if you have this under your /configuration/system.webServer/handlers section (for IIS7): <add name="EPiTraceTracker" path="TrackerHandler.ashx" verb="*" type="EPiServer.Trace.CMS.Handlers.TrackerHandler" />.
Reinstall should be quite safe.
if it is not working you are probably missing the config-settings but stil have the EPiServer Trace dll in you binary folder. Maybe you have installed them earlier or as mentioned you are using an old version. If you remove all binaries and the configs-settings, just search for "trace" you will be able to remove it from your solution. Or you could just reinstall the new version.
Hmm. Very strange. The dll is in the bin-folder, and the handler-line is in web.config. No "Live Monitor" in the CMS menu though. I'll try to reinstall and get back to you.
Still haven't solved this so maybe it's time for another try. The instructions reads "Download and unzip the Live Monitor.zip" but where do I download this zip-file??
We've got 2750 404 errors in Google Webmaster Tools cause by EPiTrace. Any idea why this is? The links can look something like EPiTrace/Handlers/TrackerHandler.ashx?pageId=1857