If you can’t get Skype to send pictures and keep seeing an error saying “this photo is unavailable” then hopefully this quick tip will get you back up and running with exchanging media.
For me I kept trying to send the pictures, and even other files like PDFs but I just kept getting the same error:
I even tried sending from my iPhone, restarted Skype several times, force closed and then finally I even rebooted the PC.
For me the solution was found when it occurred to me that I had recently changed my Microsoft Account password to make the password more secure.
It seems that Skype will carry on working if you change your Microsoft Account password and even survive a reboot with a valid auth key. Whatever it does under the hood with your images however it cannot pass them over until you have re-authorised.
I logged out of my Skype account and then logged back in again using my new Microsoft Account credentials.
After this the images started working for me again!