mha4mysql-service won't start after updating to mysql 5.7

[buktt]

Hi, we have been using the mha4mysql-service for along time, but know we are trying to upgrade to mysql 5.7 (from 5.5 threw 5.6) but the mha4mysql-service won't start after updating to mysql 5.7. we are running on Centos 6.8 and getting the error:

Wed Apr 25 14:16:44 2018 - [info] Dead Servers: Wed Apr 25 14:16:44 2018 - [info] Alive Servers: Wed Apr 25 14:16:44 2018 - [info] 10.00.187.3(10.00.187.3:3306) Wed Apr 25 14:16:44 2018 - [info] 10.00.187.4(10.00.187.4:3306) Wed Apr 25 14:16:44 2018 - [info] Alive Slaves: Wed Apr 25 14:16:44 2018 - [info] 10.00.187.4(10.00.187.4:3306) Version=5.7.20-log (oldest major version between slaves) log-bin:disabled Wed Apr 25 14:16:44 2018 - [info] Replicating from 10.00.187.3(10.00.187.3:3306) Wed Apr 25 14:16:44 2018 - [info] Current Alive Master: 10.00.187.3(10.00.187.3:3306) Wed Apr 25 14:16:44 2018 - [info] Checking slave configurations.. Wed Apr 25 14:16:44 2018 - [warning] relay_log_purge=0 is not set on slave 10.00.187.4(10.00.187.4:3306). Wed Apr 25 14:16:44 2018 - [warning] log-bin is not set on slave 10.00.187.4(10.00.187.4:3306). This host cannot be a master. Wed Apr 25 14:16:44 2018 - [info] Checking replication filtering settings.. Wed Apr 25 14:16:44 2018 - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln427] Error happened on checking configurations. Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/vendor_perl/MHA/ServerManager.pm line 396. Wed Apr 25 14:16:44 2018 - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln525] Error happened on monitoring servers. Wed Apr 25 14:16:44 2018 - [info] Got exit code 1 (Not master dead).

i'd appreciate some help.