The sad story of an incorrect file type

[Pedrus the wise]

The "incorrect file type" error hit me for the second time. The first time I thought it was a mistake on my part. This time I've lost 20 hours of work, so you can understand how frustrating that is. I worked on my project all day, and when I tried to open it in the evening, a window told me it was "impossible to perform this operation because the file type is incorrect" (in french : "impossible d'effectuer cette opération car le fichier est de type incorrect"). .

I know what you're thinking, but no, it's still .psd, and I haven't touched it. I saw on the internet that I wasn't the only one with this problem, and that there was no solution. So, bye bye my 20 hours of work! :'''')

But if there is a solution, I'm interested. 

Kind regards. 

[Trevor.Dennis]

That's a sad story Pedrus the Wise.  I wonder if this helps:

https://helpx.adobe.com/nz/photoshop/kb/error-not-a-valid-photoshop-document.html

On the face of it, probably not, but it might be worth trying some different extensions like .TIFF and .PSB  (I assume your document has a bunch of layers).  There are .PSD recover apps, but we've seen a few posts about corrupt PSD files in the years I have been helping people on this forum, and I can't remember a single one that fully recovered the file.

We have also had posts from people who regularly saved their big projects, but experienced a system crash while the file was being saved which corrupted the file.  So we have taken to saving large projects to incrementing file names just in case.

Have you closed Photoshop since seeing this error message?  It sounds like it would be a long shot in this case, but Photoshop is getting very good with it's recovery function nowadays.  If Photoshop hangs (which did not happen in your case) then the next time you open Photoshop any files that were open when the crash happened are loaded from the recovery location with 'recovered' added to the file name.   I am sure we all have our fingers crossed for you.  That's a scary amount of work to lose.