serviio log - possible error

[spudy12]

I just installed a new instance of serviio on a headless ubuntu server and was having some issues with serviio being very slow and constantly buffering
I seemed to have fixed that issue but now have some strange entries in the log file

  Code:

2014-02-10 00:46:11,994 WARN [ServiioStatusService] NullPointerException occured. Returning error code 500 to the REST layer. Message: null
2014-02-10 00:46:08,587 WARN [ServiioStatusService] NullPointerException occured. Returning error code 500 to the REST layer. Message: null
frame= 558 fps= 92 q=31.5 size= 3452kB time=00:00:23.30 bitrate=1213.6kbits/s
frame= 511 fps= 92 q=31.0 size= 3177kB time=00:00:21.34 bitrate=1219.3kbits/s
rc buffer underflow
frame= 469 fps= 93 q=31.0 size= 2906kB time=00:00:19.77 bitrate=1203.9kbits/s
frame= 420 fps= 92 q=13.8 size= 2594kB time=00:00:17.76 bitrate=1196.0kbits/s
2014-02-10 00:29:32,387 WARN [ProcessExecutor] Process /usr/local/bin/ffmpeg has a return code of 137! This is a possible error. Detailed output follows.


is the above anything to worry about?
thanks