Same here, back to 4.1.2506. Off to investigate a bit
32.907970] tvh:mtimer[1344]: segfault at e4 ip 000055df931b82e5 sp 00007fd5977fd670 error 4 in tvheadend[55df92fd6000+117a000]
Linux tvheadend 4.4.0-72-generic #93-Ubuntu SMP Fri Mar 31 14:07:41 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
using build tvheadend_4.1-2513~g635adc5~xenial_amd64.deb