Symptoms

A domain "domain.com" is not synced to name servers. In /var/log/messages there are records like

Nov  7 14:10:38 Control pdns[11453]: TCP Connection Thread died because of STL error: unknown escape sequence
Nov  7 14:10:38 Control pdns[11453]: Exception: unknown escape sequence

On the slave name server the following could be found in /var/log/messages:

Aug 25 14:49:28 ns1 named[2381]: zone domain.com/IN/pbas_resolver: Transfer started.
Aug 25 14:49:28 ns1 named[2381]: transfer of 'domain.com/IN/pbas_resolver' from 203.0.113.2#53: connected using 203.0.113.3#52658
Aug 25 14:49:28 ns1 named[2381]: transfer of 'domain.com/IN/pbas_resolver' from 203.0.113.2#53: failed while receiving responses: end of file
Aug 25 14:49:28 ns1 named[2381]: transfer of 'domain.com/IN/pbas_resolver' from 203.0.113.2#53: Transfer completed: 1 messages, 1 records, 94 bytes, 0.001 secs (94000 bytes/sec)

Cause

Incorrect DNS record in the domain.com DNS zone

Resolution

Go Top > Service Director > Domain Manager > Domains > domain.com > DNS Zone,check all domain TXT records for errors and correct erroneous ones. In our example the culprit record is

v=spf1 mx a ip4:70.34.35.210\21 ~all 

While it should be:

v=spf1 mx a ip4:70.34.35.210/21 ~all 

Issue can also be caused by a missing quote (").

Exception: Parsing record content: Data field in DNS should start with quote (")

TCP Connection Thread died because of STL error: Parsing record content: Data field in DNS should start with quote (") at position 3 of '"("v=DKIM1; p=" "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDfl0chtL4siFYCrSPxw43fqc4z"
    "Oo3N+Il220oK2Cp+NZw9Kuvg8iu2Ua3zfbUnZWvWK4aEeooliRd7SXIhKpXkgkwn"
    "AB3DGAQ6+/7UVXf9xOeupr1DqtNwKt/NngC7ZIZyNRPx1HWKleP13UXCD8macUEb"
    "bcBhthrnETKoCg8wOwIDAQAB")"'

In that case correct record should look like

("v=DKIM1;"
    "p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDfl0chtL4siFYCrSPxw43fqc4z"
    "Oo3N+Il220oK2Cp+NZw9Kuvg8iu2Ua3zfbUnZWvWK4aEeooliRd7SXIhKpXkgkwn"
    "AB3DGAQ6+/7UVXf9xOeupr1DqtNwKt/NngC7ZIZyNRPx1HWKleP13UXCD8macUEb"
    "bcBhthrnETKoCg8wOwIDAQAB")

Internal content