Possible solution:
I read the answer from spectrasonics. hoping they will fix this soon. but in the meantime, I experienced the issue of Omnisphere 2 not saving patches and multis.
if I’m only saving MULTIS and SONGS, when I reopen the song, Omnisphere will not load multi correctly. and I loose patches.
I have to save every patch, then save multi and then songs, to be able to reopen multi correctly.
https://community.cantabilesoftware.com/t/omnisphere-2-keyscape-issue-on-switching-songs/1552/52

Cubase
Always make sure to close the Omnisphere window before saving and closing the project and/or Cubase!
https://forums.steinberg.net/t/omnisphere-blank-upon-recall-what-are-the-workarounds/675383/11

User @Mixdowner says:
FIX : save the multi and if you see the file is just 10K savie each patch using the command "Save Patch As" from omnisphere into your User folder, then save your song, close cubase, reload cubase, reload the song, open Omni (it will be empty but with correct volumes) and reload each saved patch in the correct order, at that point you save your multi and it will always work, save the song and you're ok, after that if you don't change anything in Omni you can compose for hours and save your song as usual and everything works OK, however if you need to change any setting in your multi it probably won't save so once again you will need to save the single patches you've modified after the last save.
https://audiosex.pro/threads/fix-for-omnisphere-not-saving-multis.27970/

KVR User: tasty tatsyn ssys:
so my advice until you have this figured out is:
- Save the patches/presets @ -> Utility -> Save patch as -> and create a new Folder
**Note you don't need to fill out all that info/categorys/etc in preset/patch save....
just choose a name for the preset and press save... done
if you just want to overwrite a presets just select --> Utility -> Save patch quick

Spoiler: Spectrasonics - Omnisphere 2 - Support

Spectrasonics - Omnisphere 2 - Support

Saving and Managing Sounds
NOTE: Patches and Multis must be saved into a Category folder inside a user Patch Library —you cannot save at the User folder level itself. This folder can be in an existing user directory, a newly created sub-folder inside the User folder, or a new user directory. There is no need to press the “Refresh” button in the Full Browser after saving a new Patch or Multi.
https://support.spectrasonics.net/manual/Omnisphere2/25/en/topic/browser-page02

Projects
https://support.spectrasonics.net/manual/Omnisphere2/25/en/topic/browser-projects-page01

Save as Default Multi
https://support.spectrasonics.net/manual/Omnisphere2/25/en/topic/concepts-header-page03b

 

Hello everybody! 6 years later, the joke continues!

https://audiosex.pro/threads/the-la...gain-the-recall-preset-issue-time-bomb.61801/

 

As far as I can tell, the last 2048 keygen patcher for mac, creates the same unanimous response code for Keyscape, Omnisphere and Trilian. Whilst this allows them to run, I think its something in this outdated method that may be problematic for mac users at least. The new windows r2r keygen provides separate responses after entering challenge codes. I think until a new patcher is made we will be stuck in this loop hole. I could be wrong of course, but its the only real thing I see out of place.

 

R2R released fixed version, everyone can try:

 

Spectrasonics Omnisphere v2.8.1c FULL Update WIN FiXED vkDanilov | 30 November 2021 | 820 MB

Release Notes:
► no time bombs
► no keygen needed (just install)

Previous release bugs:
► Sometimes when you reload a project, patches are still reset
► Spontaneous change of patches