Had the same problem on a 5209, removed /var/run/dbus/system_bus_socket and
Result: admin server didn't answer anymore...
[Wed Jul 11 10:32:17.138661 2018] [ssl:error] [pid 13495] AH02235: Unable to
configure server certificate for stapling
I was able to connect finally on the IP of the admin server but any connection
attempts to the servername (it has a valid, official cert) time out.
Vhosts with same (wildcard) cert run OK.
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