Please follow the steps below to fix:
Step 1: Launch iTunes on computer, find Backups in Summary tab on the top menus;
Step 2: Check whether you have selected Encrypt iPhone backup. If so, please unselect it to unlock your iPhone backup.
Step3: When you unselect this option, a window pops up asking you to enter the password you've set. Enter the correct password and click OK button to unlock this backup.
Step 4: Relaunch the iPhone/iPad/iPod Data Recovery and scan your iPhone/iPad/iPod again. The software will find the data from your iPhone.