Can I install Application package versions on top of Junos OS Releases?
You cannot install Application package version 14.1X54-A1 on top of Junos OS Release 14.1X53-D10. Releases 14.1X53 and 14.1X54 are two distinct major releases of Junos OS. You can install Application package 14.1X53-A<x> where x is the latest available version of the Application package, on top of Junos OS Release 14.1X53-D10.
Similarly, an Application package for Junos OS Release 14.2R<x> is not compatible with Junos OS Release 14.2X<x>.
You cannot install an Application package on top of Junos OS releases prior to Release 14.1X53. The feature that separates J-Web for EX Series switches into Platform and Application packages is introduced in Junos OS Release 14.1X53.
You can view details of the J-Web packages installed on your switch in the About window in the J-Web interface, or in the output of the show version command in the Junos OS CLI.
For more information, click J-Web User Interface Overview.