Troubles opening a Photoshop File CC 2015.5

[franciscov38142897]

Hi everybody,

Yesterday I was working on my PC with Photoshop CC 2015.5, I saved my file normaly (ctr+s) and then I closed Photoshop. Today I opened the file again and a pop up message appeared instantlyr.

This document contains unknown data which will be discarted to keep layer editable. To preserve the original appearance  instead, choose flatten to load composite data as a flattened image.

well... I don´t want to flatten or merge it because a I was working on an animation so I need all of my layers, I don´t why this message appears, I know that can happen if the file is created on a latest version but, as i have already said, yesterday night was the last time I modified the file on my PC.

Please help me! I really need to open this project.

[Barb Binder]

This message can come up when you open a Photoshop document on an older version that the one it was created in. Double check to be sure you don't have more than one version of Photoshop installed (and didn't inadvertently open the old one).

I haven't seen this message lately, but I thought there were three options: Flatten, Cancel and Keep Layers. Are you able to select Keep Layers?

[franciscov38142897]

I just have one version of Photoshop, I don´t know why this message comes up over and over again when I try to open it.

Yes, there are three options but none of them work, for example, when I click on keep layer, all of my layers are empty and if I try the flatten option an error comes up.