Mistakenly deleted my earlier 2 comments.Coming to the problem, I've zeroed in on the culprit js file (1 out of 158 on whole app).Thanks all.

For my production publish environment "minify" is enabled for Adobe Granite HTML Library Manager.And while rebuilding the Client Libraries through /libs/granite/ui/content/dumplibs.rebuild.html tool, I am encountered with the following error:building /etc/designs/mysite/clientlib_base.min.js...error...

Thanks for sharing.Here is another solution that worked for me - http://goo.gl/K3MiTH

Steps that fixed the issue for me courtesy Daycare support.1. Stopped Region Digraph (org.eclipse.equinox.region) bundle. Not used in 6.1.2. Restart the instance3. Clear the compiled classes using http://<host>:<port>/system/console/slingjsp

Thank you all for scratching your heads along with me . Got the problem resolved with support help.

                Raised a support ticket already. Thanka nonetheless.

What is the hot fix number?Facing exactly the same issue.

The problem started only after installing SP1 and few other hot fixes. We didn't remove any bundle manually. 

Thank you Peter for your response.Tried to start Adobe CQ Experience Log Client Bundle com.adobe.cq.cq-experiencelog from felix console, it won't start and here is the corresponding snippet from error log:14.06.2016 04:31:01.179 *ERROR* [qtp480655781-349] org.apache.felix.http.jetty %bundles.pluginT...

Tried with several restart. Same result. As many as 28 or 29 bundles remaining in "installed" state.