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.

{
    LOCK(cs_totalBytesSent);
    nMaxOutboundLimit = limit;
}
uint64_t CConnman::GetMaxOutboundTarget()
{
    LOCK(cs_totalBytesSent);
    return nMaxOutboundLimit;
}
uint64_t CConnman::GetMaxOutboundTimeframe()
{
    LOCK(cs_totalBytesSent);
    return nMaxOutboundTimeframe;
}
uint64_t CConnman::GetMaxOutboundTimeLeftInCycle()
{
    LOCK(cs_totalBytesSent);
    if (nMaxOutboundLimit == 0)
        return 0;
    if (nMaxOutboundCycleStartTime == 0)
        return nMaxOutboundTimeframe;
    uint64_t cycleEndTime = nMaxOutboundCycleStartTime + nMaxOutboundTimeframe;
    uint64_t now = GetTime();
    return (cycleEndTime < now) ? 0 : cycleEndTime - GetTime();
}
void CConnman::SetMaxOutboundTimeframe(uint64_t timeframe)