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.

{
public:
    CNetCleanup() {}
    ~CNetCleanup()
    {
#ifdef WIN32
        
        WSACleanup();
#endif
    }
}
instance_of_cnetcleanup;
void CConnman::Stop()