Frequent random muting, then freezing

Yes it does.

Your system is running right out of memory, such that the OOM (out of memory) killer starts terminating processes:

Dec 09 01:05:53 mc-wohnzimmer kernel: sshd invoked oom-killer: gfp_mask=0x200d2, order=0, oom_score_adj=0
Dec 09 01:05:53 mc-wohnzimmer kernel: sshd cpuset=/ mems_allowed=0
Dec 09 01:05:53 mc-wohnzimmer kernel: CPU: 0 PID: 14214 Comm: sshd Tainted: G         C      4.3.0-10-osmc #1
Dec 09 01:05:53 mc-wohnzimmer kernel: Hardware name: BCM2709
Dec 09 01:05:53 mc-wohnzimmer kernel: [<8001f730>] (unwind_backtrace) from [<8001afdc>] (show_stack+0x20/0x24)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<8001afdc>] (show_stack) from [<80400b7c>] (dump_stack+0x9c/0xdc)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<80400b7c>] (dump_stack) from [<801d1b78>] (dump_header+0xb0/0x208)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<801d1b78>] (dump_header) from [<80161acc>] (oom_kill_process+0x268/0x458)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<80161acc>] (oom_kill_process) from [<801620c8>] (out_of_memory+0x3c4/0x408)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<801620c8>] (out_of_memory) from [<801698c4>] (__alloc_pages_nodemask+0xa6c/0xab8)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<801698c4>] (__alloc_pages_nodemask) from [<801e317c>] (pipe_write+0x25c/0x4c8)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<801e317c>] (pipe_write) from [<801d7a74>] (SyS_write+0x224/0x3f8)
Dec 09 01:05:53 mc-wohnzimmer kernel: [<801d7a74>] (SyS_write) from [<80016d40>] (ret_fast_syscall+0x0/0x1c)
Dec 09 01:05:53 mc-wohnzimmer kernel: Mem-Info:
Dec 09 01:05:53 mc-wohnzimmer kernel: active_anon:170858 inactive_anon:2360 isolated_anon:0
                                       active_file:1705 inactive_file:1874 isolated_file:0
                                       unevictable:0 dirty:0 writeback:0 unstable:0
                                       slab_reclaimable:1418 slab_unreclaimable:2420
                                       mapped:1355 shmem:2440 pagetables:650 bounce:0
                                       free:3943 free_pcp:129 free_cma:935

Once this happens, all bets are off, the system will start malfunctioning until a reboot. Don’t worry too much about which process it claims triggered it - that is only the process that tried to allocate memory when there was no memory left and is not necessarily the process(s) to blame for running the system out of memory.

You need to find what is consuming all memory. I would open an SSH session and launch ‘top’, then customise it as follows:

Press ‘c’ to show the full command line of processes, then press ‘M’ (capital M) to sort by memory usage, then press ‘W’ (capital W) to save these preferences. In future whenever you start top it will automatically start with these options so that processes are sorted by memory use and full command lines are shown.

Then just leave top running in an SSH session while you use OSMC normally, and watch the memory use of the processes. The column of interest is “RES” which is “resident set size” in Kilobytes, or how much physical memory that process is currently using.

Kodi will be the biggest memory user and by default it will typically consume between about 80MB and 120MB depending on what you are doing. If you see it going much past 150MB or so this is cause for concern. If some other program starts using a lot more memory than Kodi that is also cause for concern.

A Pi 2 has 1GB of ram, by default with 256MB allocated to the GPU, leaving 768MB available to the OS - it’s very unusual for a Pi 2 to run out of memory on OSMC unless you have installed a lot of background/3rd party software and one of those programs has gone crazy and started consuming loads of memory. Something like a torrent client is the most likely culprit.

If you have, it would be useful to list what background software you have installed and running.

PS did you have subtitles enabled at the time ? If so does it happen with subtitles disabled ?