Crontab not working in master branch

I updated my Router to the current master branch. The crontab seems not to be working. (Freshly installed it 2 times to confirm it)

root@turris:~# crontab -e
crontabs: No such file or directory
crontabs: mkdir: File exists

Turris OS version 3.6
Kernel version 4.4.51-558f71106736acb7f5ed6b90e17c0ef5-2

Weird. It’s working on nightly branch.

Well syslog gives me that:

2017-03-02T11:49:31+01:00 info procd[]: Instance cron::instance1 s in a crash loop 6 crashes, 0 seconds since last crash

//EDIT:
After flasing the newset medkit, installing all updates, switching to master branch it seems to work.