Unable to launch Cubase 8 after installing Cubase 9

Purchased/installed Cubase 9 this morning. Cubase 9.01 crashes when loading projects created in C8.0.40.

Am now unable lo launch C8 - crashes upon startup.

Am now effectively locked out of all current working projects.

OSX El Capitan

I wonder if loading C8 project in C9 corrupted it so it wouldn’t load in C8. If C8 can’t even get to the point where you can load a project in the hub, then yeah, that’s a problem. I don’t have C9 yet, so I can’t compare experiences. (I like to wait a couple of weeks to see what crops up in the forum, and to give time for early bug fixes.)

I’ve been opening projects back & forth in both 9 and 8.5 fine.

Have you done the tried and true renaming of pref folder?

Excuse my ignorance but could you by any chance point me in the direction of any instruction on how specifically to try the renaming preferences folder fix?

Check out this link: https://www.steinberg.net/nc/en/support/knowledgebase_new/show_details/kb_show/safe-start-mode-resetting-the-cubase-preferences.html