Sound on one project suddenly not working

Cubase
1

One project suddenly dont have any sound. Any new sound file will also not play sound (unlike some similar posts here).
Checked the latest backup and there all midi files just say “no license found please swith to steinberg activation manager for more info” when i try to open them up. All other tracks that are not helion 3 do work though. This message does not come up in the latest version on the project where nothing works. The project also previously worked fine weeks after the backups were made.
The bars will move if I play it in cubase but there is no sound coming. If I export the project the file will be soundless but still take up data as if there was no issue.

All other projects works just fine.

2

Hi,

Make sure, you have the latest update of HALion Sonic SE installed, please.

Start Steinberg Activation Manager and make sure, your Cubase has been activated.

3

As I said in the post, HALion works perfectly in all other projects its just this one song this happens in.
I "solved " it by creating a new project and just draging all the files into that new project . Still have no clue what the issue was or how to avoid it recurring.