Hi,My name is***** will try my best to help you with your question.
Try transferring one of the pictures to a computer and rename it to have just one ending - .jpg
Then try viewing it on the computer.
Try viewing it with some different apps on the computer.
Let me know if you can successfully view it there...
What file size are the affected pictures?
If you take some new photos on the phone now, can you view them ok?
If the account is not activated or synced then the pictures will not go to the Cloud.
However you could try logging in to your Cloud account to check, just in case.
When you say you "lost" pictures, do you mean they disappeared completely from the phone, or they turned black?
Are the black pictures only 4kb in size? If so, that is extremely small and those files will contain no image.
Let me check with the other techs if they have any idea what is going on here...
Can I connect to your computer to view the images and see if I can fix it for you?
Great! I am sending you the remote assistance offer now.
Okay, thank you.