ISSUE: Sonic Halion SE missing in Cubase 7.5 after installing 10.5 pro

Hi everybody,
I saw various similar posts but I didn’t find an answer so I start a new thread.
I recently installed Cubase 10.5.2 but I didn’t unistall the old 7.5 so I can still run both; today, trying to open some old project, I received an error message (see attachment).
I searched for the plugin in the location showed in the plugin manager but it seems to be completely missing…
If I open the project in Cubase 10.5 everything is ok and halion Sonic Se3 is starting.
Can someone help me? I still need to run 7.5 for a while.
Many thanks,


Just a guess, because I don’t remember the HALion Sonic SE version in Cubase 7.5. So…

I expect, there was an older HALion Sonic SE version in Cubase 7.5 than it is in Cubase 11 now. I expect the old HALion Sonic SE version has been rewritten/updated by the new version, once you have installed Cubase 10.5. But, it might be, Cubase 7.5 doesn’t recognise the new HALion Sonic SE as the same plug-in as the old one. Therefore it says, the plug-in is missing.

If all of this is true, an installation of the old HALion Sonic SE (from the Cubase 7.5 Full Installer) might fix it.

Just a guess…

Hi Martin,
do you mean I have to reinstall Cubase 7.5?
How could I reinstall only the “old Halion”?
Thank you,


I believe Cubase 7.5 Full Installer contains the HALion Sonic SE installer.