Hi Oleg,
Thanks for your query !
I would like to inform that the functionality to drag and drop a program in LDK Envelope for protection is available in LDK 7.6. Could you please try to add desired program (exe,dll) using 'Add Programs' button and share in case any error appears under log message in Envelope.
Also try to drag and drop any of our sample program available at location C:\Program Files (x86)\Gemalto Sentinel\Sentinel LDK\VendorTools\VendorSuite\samples and share the behavior.
Kind Regards,
Gaurav Bhanot