Corel DRAW 2017: Saving a Project in X5 Format - Compatibility with Older Versions

Hello, I am a beginner so if I wrote something wrong, please move it

So this is how I have CorelDRAW 2017 version and in this version I also have a "project" unfortunately it has to be saved in X5 version. I am green at this, so please help, it is a very urgent matter.

It is possible to use older versions but only up to 11: /

Save to version 15.0, powered by X5

In general, the Corel to 12 is flying, the above works like a coal car, so I am at work, a smart computer scientist, installed X7 and here it made everything worse.
Saving "Save AS" to version 12 crashed when opening in Corel 12.

I found this way because ole works.

I open files in X7 and open pure Corel 12. In Corel X7 I select and copy CTRL + C to the memory buffer.
I'm going to Corel 12 and doing CTRL + V and pasting from the memory buffer. And so page after page.
Then in Corel 12, when I write it down, it works.