Saving files compatible to older version 2018 to 2017?

I am having so much trouble with Corel2018 with crashes and file save errors, that I am worried about losing access to important work  And as such, I am considering switching back to Corel 2017 before I lose access completely.  I had fewer issues with Corel2017 and fewer complaints.

But obviously, every file I have updated to 2018 has been resaved in 2018 format and will now not open in 2017.

So, can I save (in 2018) my files, to be compatible with an older Corel version like Corel2017?