since upgrading from 299 to 303 we cannot make any configuration changes to
build jobs via the web interface

• this is true for any type of our existing jobs
• this does not happen for newly created free style jobs

workaround: remote to machine running hudson, change job config files directly,
reload config via web interface

possibly related issue: #3495
https://hudson.dev.java.net/issues/show_bug.cgi?id=3495

we also did plugin updates/installations together with the upgrade in one go ...
I guess, we won't do that ever again ... too cumbersome to track down problems
origin