Arul, you can try to recover the app restore a backup file from Qlik Sense directory.
Rename this file to .qvf and try to import APP in the QMC.
In order to discover the application ID, on the QMC, select on the top right the option "ID".
This is a workaround and option. Many times works.
Try opening the QVFs in Qlik Sense Desktop without loading the data (right click on the file and open without data).
Tried for Qlikview, it worked not sure about qlik sense.