Having a nightmare with Cubase 12. I have a 16 user license at a school however I’m finding Cubase to be really unreliable using VST instruments…for some students it seems ok for others they lose all Halion content or Groove agent content…on the same computer as other users have been ok on…this is happening all the time, it’s pot luck wether you have VST content or not…
The IT dept are at their wits end even to the point of considering ditching Cubase for some other sequencer…even though it means having to learn then teach the students from scratch it just might be worth it for the sake of stability and reliability… 
Just to clarify: On one computer the same account - one day Cubase recognizes the plugin content, other day it won’t, then on another day it will again?
Hi,
To me, it sounds like a permissions issue.
More details about when it’s working and when it’s not working (what is different in the accounts) might bring some light.
All computers are identical regarding spec and software…students tend to use the same computers…however yesterday two students who have been working successfully lost all their VSTi content… I loaded up their track from my staff computer and the content was there. I moved them to other computers and that had previously been used and were fine but all content was missing…as an education centre we are unable to continue with this as it’s effecting exam work.
Correct
Never heard about such a phenomena.
I did encounter the loss of some of the plugin content myself once. Here is what fixed it for me on a Windows system:
Close Cubase.
Open a Windows Explorer window.
Type in %appdata%/steinberg/Cubase 12_64 in its location bar.
If you use Cubase Elements the name of the Cubase folder will be different, kindly look manually for it.
Inside the folder locate the file mediabay3.db and rename it.
On the next start of Cubase the a/m will be created by Cubase anew from scratch.
There might be some loss of meta data in the MediaBay because of this but I am not sure to what extent. If you guys didn’t do extensive manual tagging of media files in MediaBay you’ll be fine either way.
If you use Macs the Cubase folder will be located in /Library/Preferences// under your home directory
This is the most efficient route to follow.
As a side note, since you do have IT guys, just before doing so, they could give a check to the database’s status, if for example it’s corrupted; Changing app is usually much harder than restoring a db.
A PRAGMA integrity_check would do.
As a final note, since mediaBay involves many filter areas, maybe you should check these as well?
I have had those issues, I have done a full reset of the system and installed only Cubase then other things and I try not to install too many funny things with ilock and other licensing software. I had no issues ever since!