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.

{
                CAddress addr(CService(), NODE_NONE);
                OpenNetworkConnection(addr, false, NULL, strAddr.c_str());
                for (int i = 0; i < 10 && i < nLoop; i++)
                {
                    MilliSleep(500);
                }
            }
            MilliSleep(500);
        }
    }
    
    int64_t nStart = GetTime();
    
    int64_t nNextFeeler = PoissonNextSend(nStart*1000*1000, FEELER_INTERVAL);
    while (true)
    {
        ProcessOneShot();
        MilliSleep(500);
        CSemaphoreGrant grant(*semOutbound);
        boost::this_thread::interruption_point();
        
        if (addrman.size() == 0 && (GetTime() - nStart > 60)) {
            static bool done = false;