Generic or SSL connection errors

Please see Proxy_communication_errors first for SSL or communication errors, which aren't specific to this particular proxy action.

Unable to retrieve DHCP entry for ...MAC... ([Net::LeaseConflict]: MAC/IP)

This was a bug in Foreman 1.5.0, fixed in 1.5.1 (bug #5637), typically seen when using Discovery. It was mistakenly believing DHCP conflicts existed between DHCP leases and new DHCP reservations.