Current bitcoin-master on testnet, `maxconnections=8` in the config file. Running in VM that doesn't have public IP and is not reachable from the Internet.

Wait until you have 8 peers.

```
telnet localhost 18333
```

It will result in:

```
Assertion failed: (nMaxInbound > 0), function AcceptConnection, file net.cpp, line 973.
```

First found in https://github.com/bitcoin/bitcoin/pull/8996, but can be reproduced on master.

{
            CDataStream::size_type pos = GetRand(ssSend.size());
            char ch = (char)GetRand(256);
            ssSend.insert(ssSend.begin()+pos, ch);
        }
        break;
    }
    
    
    Fuzz(2);
}
unsigned int CConnman::GetReceiveFloodSize() const { return nReceiveFloodSize; }
unsigned int CConnman::GetSendBufferSize() const{ return nSendBufferMaxSize; }
CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, const std::string& addrNameIn, bool fInboundIn) :
    ssSend(SER_NETWORK, INIT_PROTO_VERSION),
    addr(addrIn),
    nKeyedNetGroup(nKeyedNetGroupIn),
    addrKnown(5000, 0.001),
    filterInventoryKnown(50000, 0.000001)
{
    nServices = NODE_NONE;
    nServicesExpected = NODE_NONE;
    hSocket = hSocketIn;
    nRecvVersion = INIT_PROTO_VERSION;
    nLastSend = 0;
    nLastRecv = 0;
    nSendBytes = 0;
    nRecvBytes = 0;
    nTimeConnected = GetTime();