[Samba] Connection problems, laptop to server

[Anne Wilson]

I'm having problems connecting from my laptop, and the logs show

 lib/util_sock.c:send_smb(769)  Error writing 116 bytes to client. -1. (Broken 
pipe) : 1 Time(s)
 lib/util_sock.c:write_data(562)  write_data: write failure in writing to 
client 192.168.0.91. Error Broken pipe : 1 Time(s)
 libsmb/smb_signing.c:srv_check_incoming_message(737)  
srv_check_incoming_message: BAD SIG: seq 2 wanted SMB signature of : 6 
Time(s)
 libsmb/smb_signing.c:srv_check_incoming_message(741)  
srv_check_incoming_message: BAD SIG: seq 2 got SMB signature of : 6 Time(s)

Could someone please give me some idea of where to look for the problem?  
smb.conf looks fine, and users and groups are identical by name and ID. 

Thanks

Anne