Hello All

First time poster so sorry if i post in the wrong place / its a repeat (I did check couldn't seem to find the answer).

I have two virtual machines using samba 4.1.6 (Come on apt repository). One is setup as a DC and the other is a domain joined file server. Now for typical day to day use this works fine, domain clients can log on and access the file server drives (Mapped through GPO).

But I have a strange issue where the clients access to the file server will periodically drop out (seemingly random times) and come back again 5 minutes later. I have logging on per machine (Only level 1) and i can see an interesting when looking at the machine log file that says.

[2016/03/25 12:33:55.602091, 1] ../source3/smbd/sec_ctx.c:85(become_gid)
WARNING: using gid -1 is a security risk

I tried googling it and couldn't find any results.

Anybody got any ideas?