If you are having issues updating the Jabiru J160/J170, stuck at decompressing 1.4.5 package, try this:
Close your FS2020 session.
Go into your MSFS2020 Official Folder (eg: mine is D:\MSFS2020\Official\OneStore). Find the iris-aircraft-jab folder. Either delete it or move it OUT of your MSFS2020 tree. Also, make sure you don’t have an iris-aircraft-jab-1.4.5.fspatch or iris-aircraft-jab-1.4.6.fspatch file in your main OneStore directory. Delete/Move them if you do.
Restart MSFS2020, go into Profile, Content Manager. You should now see a package listed as “Not Installed”. Retry the redownload/reinstall. It SHOULD complete this time.