After upgrade of the jenkins server to Jenkins ver. 2.176.2 and all plugins to the latest version, all of our pipeline jobs are showing this (see screenshot) and we try to modify it to Pipeline script from SCM and save the configuration, and reopen the configuration of the job it reverts back the screenshot!
what is weird that in the jenkins home directory, the configuration in the job is there in the xml files, it is just not parsed on the GUI!
Even when we create new jobs and save it as pipeline script from SCM, the display always revert to Pipeline script! And there is nothing in the logs that can point us to what might be the issue