With every new CIAO release, it is likely that some parameter files have changed; new parameters may be added and occasionally old ones removed or renamed. In most situations, this should be picked up automatically by the CIAO parameter interface and you will see a message such as:

unix% plist ciao
Warning:  found possibly out of date user parameter file, renamed to /home/ciaouser/cxcds_param/ciao_20021113.09:29:58.par

... Normal output from 'plist ciao' ...

However, this is not guaranteed to work in all cases - in particular with scripts with a parameter interface - which may result in strange behaviour.

We therefore strongly recommend deleting the old parameter files or renaming the parameter-file directory before running any new version of CIAO. CIAO parameter files are generally stored in the directory $HOME/cxcds_param/.

More information on parameter files is available in the Introduction to CIAO thread.