There are a couple of things to check if you are having problems importing the CSV file for passcode photos.
1) You don't have the photo filename with the extension in the CSV file. The filename in the CSV file needs to be formatted like DSC_001.jpg
2) Sometimes the encoding of the CSV file when exporting it from excel or something similar can be off. If you have a google account you can try the following.
- Go to Google Drive.
- Click the "+ NEW" Button then File Upload
- Upload your CSV file.
- Open the file in the spreadsheet editing then go to File -> Download and download it as a CSV file.
- Then try importing that new file for the passcodes.
3) Settings -> Photo settings and make sure the "Passcode Photos Search By" option is set to "In the title (or upload CSV file with passwords)".