Hello Pawel, a couple of thoughts or should I say a "shot in the dark".

Are your projects folder the same in both versions?

Did you create a sub-folder in your project folder in v11 that's not in v12?

(Check both under Preferences, Project Folder and click on the folder icon at the right to see the folders. Or use windows explorer.)

Do you have a link or something in v11 relating to i-tunes?

You may need to make a copy (different name) of your v11 project and remove all that is NOT native to website x5 and see if that imports in.

Tomorrow is monday so incomedia should be checking in soon. 

Kind Regards

Donald

i am having the same problem

"[Could not find file library.xml]"

when i try to copy my files over from my X5 11 director to the X5 12 directory. please tell me how i open my 11 project in 12? this is very frustrating i don't have the time to wait for answers to something that should be "easy" - this is suppose to be an "upgrade" after all. why am i not able to simply open up my X5 11 directly in X5 12 without having to jump thru hoops?

please tell me how to open my X5 11 pro in my new X5 12 pro ASAP

***

F.A.Q. COMPATIBILITY
Can I open projects created with WebSite X5 Evolution 9, 10 or 11 in WebSite X5 Evolution 12?

Yes, projects created with versions 9, 10 and 11 can be opened and updated in WebSite X5 Evolution 12.

It's easy to do: 

• open your project in WebSite X5 Evolution 9, 10 or 11, go to Step 5 and select Export the Project, giving the destination folder name. This creates a compressed .IWZIP file which contains both the project file and the linked files.
• Then start WebSite X5 Evolution 12 and open the Project Selection window, click on the Import button and select the .IWZIP file of the exported project
  
• At the end of the process, the file will appear in the list of existing projects. Select the imported project and click on the Next button to make your changes. 
  

The time it takes to import a project depends on its size and the number of linked files: the .IWZIP file has to be decompressed and the library and preview files have to be created. These operations are only done the first time: the next time you open the file, it will be much quicker.

You'll find more information in the document “Converting Projects”

thank you very much