Owncloud not working after upgrade to php 7.0.3

[eatmorepets]

Hi there,
not sure if this is the right place, but my owncloud silently stopped working after upgrading php from 7.0.2-2 to 7.0.3-1.
By silently I mean- I don't get any meaningful error message (meaning none) by either owncloud (running "occ check" yields, well, nothing, the logs just complained about some missing IMAP extension like they always did), apache (everything else seemed to work here as expected - haven't checked any php related stuff here though, error logs where empty), nor php itself (though I am not sure where to look for errors here)

Downgrading to 7.0.2-2 fixed it immediately.
Any ideas?