I am using both the Windows and Android apps...I backed up Daylio and then went into the Android app and selected setting/migrate from other app/Daylio/ and got the message "Error No .csv in .zip file found". When I select Import diary and select the Daylio backup file I get the message "Error: file is not a database".\
When I use the Windows app I am unable to select the DAylio backup file as it requests a *.diary file.