how can i mount drives formatted with omv3 in omv2?

Hello everyone,

i just decided to switch my ancient Windows Home Server to OMV. Since WHS uses Drive Extender to manage all Drives as a single pool all my files where spread over all disks in some arcane way i was not sure i understood correctly, i copied as many files as would fit on my 2T USB HDD then removed one HDD from the Drive Extender Pool, set up an "temporary" OMV on a spare pc, formatted the removed HDD to ext4 and copied the files over.
Since i was still in the "try out" phase i sometimes booted a OVM 2 installation and sometimes an OVM3 installation. Assuming i just copy files to a data disk i would not matter what version of OVM i use at this time
Today finally i finished the copy marathon and was ready to set up my "real" OMV Box using OMV2, but found out that at least one disk had some filesystem problems that could not be fixed with OMV telling me to get a newer version of fsck. so i gave omv3 a try and it fixed the problems without problems, but i found out that at least one plugin i want to run is not (yet) running on OMV3, so i went back to OMV2 which now booted without problems since the file system was fixed.
but now i wanted to mount the data disks but only some work, i assume the ones formatted with OMV3 wont mount and give me errors.

tl;dr:
Is there a way to mount Volumes formatted with OMV3 under OMV2?

first plugin i wanted to install was sonarr, but i got an error message like "openmediavault expected 3.0.13 but 3.0.68 to be installed" or something like that. dont have 3 beta running anymore.

when i try to mount a filesystem created under 3beta with OMV2 i get the following error message:

Failed to mount '458226a2-7957-4b50-9acb-74cbbd11180a': mount: wrong fs type, bad option, bad superblock on /dev/sdd1, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so

sadly i could not get the disks mounted under V2 and i could not install nzbget in V3. so i formatted a drive in V2 mounted it in V3 and copied all the data of on disk to the empty disk. formatted the now empty disk again under V2 and again copied the content of another disk to it in V3. after i did that with all disk, i now have all my files on V2 HDDs and everything is working fine