[molpro-user] Error: SPIN not possible

["Piotr J. Bardziński"]

Dear Listmembers,

Sorry to bother you in the matter of my interest, but I am a Molpro user 
and have a problem I can`t fix.
I would appreciate it if you would mind advise me how to deal with 
that... Namely, I want to perform an RI-MP2
calculation of interaction energy between two quarternary ammonium ions 
with one long aliphatic chain.
Here is the error communicate extracted from the end of output file:

MOLECULE CHANGED: INITIALIZING OCCUPATION AND DUMP RECORDS

nelec= 177  ms2=   0
? Error
? SPIN not possible
? The problem occurs in putocc

GLOBAL ERROR fehler on processor   0

Note hat the input lines were:

***,  graphene_opt histydyne_opt
memory,175,m
gdirect
basis=cc-pVDZ
wf,charge=2,symmetry=1,spin=0
geomtyp=xyz
nosym,noorient
geometry={
(...)
df-hf,df_basis=vtz
df-mp2

As I neither have an idea what to do with that, nor found any solution 
on the internet forums, I`ve decided to ask you, this question.
I would be grateful if you look at my case...

Best regards!
Piotr B