I had the same problem. by mistake, you set the config file /etc/hostapd/hostapd.conf to DAEMON_OPTS instead of DAEMON_CONF.
1. Add DAEMON_CONF="/etc/hostapd/hostapd.conf" to /etc/default/hostapd.
2. Comment DAEMON_OPTS= ... or remove all the line.
3. service hostapd restart.
Another possibility is about "Wifi Country Code". Run raspi-conf and go to 4 ...
Sounds like an undervoltage situation. Keep in mind that phone chargers aren't the best when used as a PSU. Get a better charger or buy the raspberry pi official PSU.
I used to have this problem as well.
What you have purchased isn't only an antenna to replace the built-in antenna (I don't believe that's possible), it is a complete new WiFi transmitter/receiver that can be used in addition to the built-in WiFi. If you do not need the built-in WiFi so just don't configure/use it. You can also completely disable it by adding this option to /boot/config.txt:
Developer of RaspAP here. The project does not lock the file system or interfere with other services. I installed mosquitto after RaspAP, enabled the service and rebooted. Confirmed it's active and listening on port 1883:
sudo netstat -ltnp | grep -w ':1883'
tcp6 0 0 :::1883 LISTEN 405/mosquitto
Check the output of mount -l and ...
If you are open to use another modern all-in-one networking environment without needing additional helpers like hostapd, dnsmasq or bridge utils you can use systemd-networkd. It makes life easier. It is part of the default Raspbian image and you only have to enable and configure it. Here is a tested and working setup for what you want to do: Configuring ...
What you want is a bridge device. This would be "br0" instead of "wlan0" and "eth1".
Then I believe you list the bridged devices on a "bridge_ports" line in /etc/network/interfaces or equivalent.
In any case, you install bridge-utils, and the "brctl" command gets run automatically when you run ifup and ifdown.
You might read /usr/share/doc/ifupdown/...