What is a "standard" CIAO installation?
The prism package was removed in CIAO 4.14.
If you have installed a customized version of CIAO, it is possible that some of the analysis tasks will fail due to a missing package. Similarly, the scripts may contain a dependency on any of the other standard components, and will fail if one is missing.
|ciao, ciao-contrib, ds9, marx, sherpa
|caldb, caldb_main, acis_bkg_evt, hrc_bkg_evt
|core, graphics, tools, obsvis, sherpa
|CALDB_main, CALDB_acis_bkgrnd, CALDB_hrc_bkgrnd
You do not need all these packages to use CIAO; in particular the CALDB packages are no always needed (and you can use the download_obsid_caldb script to download a subset of the CALDB just for the Chandra data you wish to a analyze).