We recently updated iExplorer to work with iCloud Photo Library enabled iPhones or iPads which is a setting that allows you to store your Camera Roll photos and videos in iCloud instead of keeping all of those large files on your iPhone or iPad. If you see that several of your photo or video files are grayed out in the Photos section of iExplorer or in the Media/DCIM folder, that is a pretty good indicator that you do have iCloud Photo Library enabled. Or, if all photo or videos files are grayed out, and iTunes is asking you to enter the passcode for your device, you'll need to enter the passcode on the screen of your iPhone, iPad or iPod Touch and then try again. Beginning in iOS 8, for added privacy and security, Apple has designed it to where you need to unlock an iOS device before you can access all of its photos and videos (unless you use the same PC or Mac where you normally sync the iPhone or iPad).
When iCloud Photo Library is turned ON and a photo or video is only stored in iCloud, your iPhone or iPad only has a tiny, low resolution version of that photo or video file which is too tiny to be viewed without a lot of blur and distortion, and iExplorer will only transfer a photo or video if the full resolution file is physically stored on your device. Most people don't want to keep a tiny version of their photos since you can't hardly make out anything. When you select a grayed out iCloud photo or video in the Photos section, the file information in the right preview panel will show that the Location is iCloud.
If you need to transfer any of those grayed out photos that are only stored in iCloud, you'll need to change a setting to get all of your iCloud photos and videos downloaded to your device. To do this, just tap on Settings > Photos & Camera, and you should see the switch for iCloud Photo Library turned to ON. If it is set to ON (green), and if you have it set to "Optimize iPhone Storage", you'll need to change that setting to “Download and Keep Originals” instead which will then take some time to download the original, full versions from iCloud, but after they are done downloading, try using iExplorer's Photos section again, and the files will no longer be grayed out. If you try to export a grayed out iCloud-only file before the original has been downloaded, it won't work because, as mentioned above, iExplorer can only transfer photo or video files if the full version is physically stored on your iPhone to iPad. You could still access and transfer the tiny thumbnail versions of the photos or videos in the Media/PhotoData folder, but it will be so tiny that if you try to expand it larger, the image resolution will be very blurry and essentially unusable.