After restarting the CA PAM server, PAM shows "Error loading config" and is not accessible.
This PAM was configured with DHCP before and was assigned an IP address.
When PAM was restarted, there were no DHCP server anymore thus no IP was getting assigned.
In the "console.log" following can be found.
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
Running ifconfig -a after DHCP for debugging purpose
eth0 Link encap:Ethernet HWaddr 00:XX:XX:XX:XX:XX
inet6 addr: xxxx::xxxx:xx:xx:xxxx/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11 errors:0 dropped:0 overruns:0 frame:0
TX packets:15 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:862 (862.0 B) TX bytes:3042 (2.9 KiB)
As can be seen above, there was no ipv4 address assigned.
Manually configuring the IPv4 on PAM resolves the problem.