Parameters dissappeared when configured (after upgrade of jenkins? Not sure anyway).
Upon accessing the job and entering the configuration of the job and unmarking "This project is parameterized" and saving I get the following in the jenkins log:

Dec 15, 2016 3:02:44 PM com.joelj.jenkins.eztemplates.exclusion.JobParametersExclusion merge
INFO: +++ new parameter [RELEASE]
Dec 15, 2016 3:02:44 PM com.joelj.jenkins.eztemplates.exclusion.JobParametersExclusion merge
INFO: +++ new parameter [SPIN]
Dec 15, 2016 3:02:44 PM com.joelj.jenkins.eztemplates.exclusion.JobParametersExclusion merge
INFO: +++ new parameter [PROJECT]
Dec 15, 2016 3:02:44 PM com.joelj.jenkins.eztemplates.exclusion.JobParametersExclusion merge
INFO: +++ new parameter [SUFFIX]
Dec 15, 2016 3:02:44 PM com.joelj.jenkins.eztemplates.exclusion.JobParametersExclusion merge
INFO: +++ new parameter [KEEP_WS]
Dec 15, 2016 3:07:59 PM hudson.plugi

After this the parameterized build works just fine again.

It seems like the data is still available but just needs to be resynced.
Any advice on how to resync all the data for eztemplates would also be nice as I currently have 100+ jobs for which I have to go through the gui to enable the parameters again.