Hi there!
New user here, I have installed nexcloudpi in a raspberrypi and everything was looking good until I ended the configuration and when trying to access nextcloud I get a generic “Internal Server Error” 
I don’t know how to look at the log. The system info is:
System Info
| NextCloudPi version | v1.4.5 |
|---|---|
| distribution | Raspbian GNU/Linux 9 \n \l |
| automount | yes |
| USB devices | sda sdb |
| datadir | /media/USBdrive/ncdata (doesn’t exist) |
| rootfs usage | 3.4G/15G |
| swapfile | /var/swap |
| dbdir | /var/lib/mysql |
| Nextcloud check | error |
| HTTPD service | up |
| PHP service | up |
| MariaDB service | up |
| Redis service | up |
| Postfix service | up |
| internet check | ok |
| port check 80 | open |
| port check 443 | open |
| IP | 192.168.1.39 |
| gateway | 192.168.1.1 |
| interface | wlan0 |
| certificates | xxxxx.ddns.net |
| NAT loopback | yes |
| uptime | 24min |
Can you help me?