Can not mount a raid data drive (worked on 2.1)

Hello community.
I had some issues after installing omv 3. Somehow I could not mount my data drives due to this error, when trying to mount the raid as a data drive (like it was before in omv 2.1), it said
...mount: wrong fs type, bad option, bad superblock on...
When going back to omv 2.1 it worked well again.
So I tried to install omv 3.0.59 again, but the problem appeared again.
Someone with the same issue around?
Any workaround? I really want to install omv 3.0.59 becahuse I want to install nextcloud 11.
Thanx for your help in advance.