Cubase 9.5.21 cannot open Cubase 9.5.30 Project files

Hi Can anyone help,
Having multiple problems where different versions of cubase wont load projects created in other versions of Cubase,
this is on 2 different computers
For example Cubase 9.5.21 wont open projects created in 9.5.30

on the other computer Cubase 9.5.30 wont open projects created in 9.5.21.

Every time it shows message Project “xxxxx.cpr” was created with Cubase Version 9.X.XX. This program version cannot load it.

We have re-installed, reset prefs to no avail.
Anyone else experiencing this nightmare?

…FWIW, I’ve just checked on my Windows 7 system which has Pro 9.5.30 and Elements 9.0.40 and projects from Pro 9.5.30 open just fine in the older Elements version.

I think my Pro version on my Win 10 PC is 9.5.20 so I’ll check that later.

Thank you, I’m sure this can’t be happening for everyone as there would be more people talking about it. but we are getting pretty stuck with projects.
we are having the issues on a windows 10 and windows 7 system.
win 10 running 9.5.30 opens every project,
win 10 running 9.5.21 wont open 9.0.30 projects or 9.5.30 projects
win 7 running 9.5.30 wont open a 9.5.21 projects
win 7 running 9.5.21 wont open a 9.5.30 project

I have the same problem on mac.
I had to install the 9.5.0 to open 9.5.20 project that crashed on 9.5.30