error: cannot bind non-const lvalue reference of type ** to an rvalue of type ** [duplicate]

I am working on compiling some old api code that was written back in mid to late 90's, it is written in C++98 and I am using GCC on linux.

I have this line of offending code:

UnpackCommunityData(data.insert(std::map<long, CommunityData>::value_type(ReadLong(), CommunityData())).first);

The above line leads to this error:

msg/Profile/SMsgProfileMsgs.cpp: In member function ‘virtual void WONMsg::SMsgProfile2DownloadCommunityTreeReply::Unpack()’:
msg/Profile/SMsgProfileMsgs.cpp:1410:107: error: cannot bind non-const lvalue reference of type ‘std::map<long int, WONMsg::CommunityData>::iterator&’ {aka ‘std::_Rb_tree_iterator<std::pair<const long int, WONMsg::CommunityData> >&’} to an rvalue of type ‘std::_Rb_tree_iterator<std::pair<const long int, WONMsg::CommunityData> >’
UnpackCommunityData(data.insert(std::map<long, CommunityData>::value_type(ReadLong(), CommunityData())).first);
                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~

These are the definitions:

    struct CommunityData {
     long CommunitySeq;
     long TrustLevelId;
     std::wstring Name;
     std::wstring Descr;
     long JoinByInvitationOnly;
     long ParentCommunitySeq;
     std::vector<long> ChildrenSeq;
    };
    std::map<long, CommunityData>           data;
    void UnpackCommunityData(std::map<long, CommunityData>::iterator&);

void SMsgProfile2DownloadCommunityTreeReply::UnpackCommunityData(std::map<long, CommunityData>::iterator& itInfo) {
    itInfo->second.CommunitySeq = itInfo->first;
    itInfo->second.TrustLevelId = ReadLong();
    ReadWString(itInfo->second.Name);
    ReadWString(itInfo->second.Descr);
    itInfo->second.JoinByInvitationOnly = ReadLong();
    itInfo->second.ParentCommunitySeq = ReadLong();

    unsigned short n = ReadShort();
    for (int i = 0; i < n; ++i) itInfo->second.ChildrenSeq.push_back(ReadLong());

    databyname.insert(std::map<std::wstring, long>::value_type(itInfo->second.Name, itInfo->second.CommunitySeq));
}

I'm not well versed in templates in C++, so I do not have a clue as to how to fix this error.

I would like it if someone could walk me through the error and solution.