Gluster users - Apr 2016 - 0-dict: dict|match|action is NULL [Invalid argument] warning

Hello,

I just upgraded my 2 nodes replica from GlusterFS 3.7.8 to 3.7.10 on Debian 8
and noticed in the brick log file (/var/log/glusterfs/bricks/myvolume-brick.log)
the following warning message each time I copy a file. For example I just copied
one single 110 kBytes file and got 19 times the same warning message:


[2016-04-03 10:29:30.023661] W [dict.c:1282:dict_foreach_match]
(-->/usr/lib/x86_64-linux-gnu/libglusterfs.so.0(dict_foreach_match+0x65)
[0x7f40f2fd6ac5]
-->/usr/lib/x86_64-linux-gnu/glusterfs/3.7.10/xlator/features/index.so(+0x3940)
[0x7f40e6f6d940]
-->/usr/lib/x86_64-linux-gnu/libglusterfs.so.0(dict_foreach_match+0xe1)
[0x7f40f2fd6b41] ) 0-dict: dict|match|action is NULL [Invalid argument]


This warning is present on both nodes. So my question now is, what does it mean
really? and is it problematic? do I need to do anything?

Regards
ML