What do these error messages mean?

This is running on an AWS AMI EC2 Linux instance in a PHP script using dblib and PDO to connect to remote Sybase databases (Sybase version 11.0.1.2596). The server has freetds with these settings: Compile-time settings (established with the "configure" script) Version: freetds v0.91 freetds.conf directory: /etc MS db-lib source compatibility: yes Sybase binary compatibility: yes Thread safety: yes iconv library: yes TDS version: 4.2 iODBC: no unixodbc: yes SSPI "trusted" logins: no Kerberos: yes Sometimes when we run queries on the sybase computers we get an error like this (the token can vary): TDS: unexpected token 95 (severity 0) [(null)] The query sometimes runs even after this error and sometimes fails. I have searched online but I can't find what this error means or how to fix it. Here is an example of one of the queries: -- 999 | Hammil | 2017-04-05 08:23:29 SELECT 999 as 'site_id', (select rest_name from micros.rest_def) as 'location', now() as 'dt_run', emp_seq, employee_number as 'obj_num', last_name, first_name, check_number, xfer_from_check, xfer_from_type, xfer_to_check, xfer_to_type, check_id, table_number, table_name, group_number, cover_count, order_type, order_type_name, business_date, check_open_date_time, check_closed_date_time, table_open_date_time, printed_count, sub_ttl, tax_ttl, auto_svc_ttl, other_svc_ttl, paymnt_ttl, amount_due_ttl, sp_error FROM micros.micros.v_R_guest_checks x where x.check_closed_date_time is null; Sometimes we get this error: SQLSTATE[HY000]: General error: 20047 DBPROCESS is dead or not enabled (severity 1) [(null)] When this happens, I can run nc -v -w 4 xxx.xxx.xxx.xxx 2638 and it returns Connection to xxx.xxx.xxx.xxx 2638 port [tcp/sybaseanywhere] succeeded! but I will continue to get the error for a few minutes and then it goes away.