MySQL Error wth Relay logs - Could not open relay logs file for logging We are receiving the following error.

2016-03-08 15:32:09 1184 [ERROR] MYSQL_BIN_LOG::move_crash_safe_index_file_to_index_file failed to move crash_safe_index_file to index file.

2016-03-08 15:32:09 1184 [ERROR] MYSQL_BIN_LOG::add_log_to_index failed to move crash safe index file to index file.

2016-03-08 15:32:09 1184 [ERROR] Could not use (null) for logging (error 9). Turning logging off for the whole duration of the MySQL server process. To turn it on again: fix the cause, shutdown the MySQL server and restart it.

2016-03-08 15:32:09 1184 [ERROR] Could not open E:\Program Files\MySQL\MySQL Server 5.6\data\bin_relay_logs\relay\mysql-relay-log.001641 for logging (error 9). Turning logging off for the whole duration of the MySQL server process. To turn it on again: fix the cause, shutdown the MySQL server and restart it.

2016-03-08 15:32:09 1184 [ERROR] Slave I/O: Relay log write failure: could not queue event from master, Error_code: 1595

2016-03-08 15:32:09 1184 [ERROR] Slave I/O: Relay log write failure: could not queue event from master, Error_code: 1595

2016-03-08 15:32:09 1184 [ERROR] Error reading relay log event: error switching to the next log

2016-03-08 15:32:09 1184 [Note] Slave I/O thread exiting, read up to log 'mysql-bin-log.000821', position 4

2016-03-08 15:32:09 1184 [ERROR] Slave SQL: Relay log read failure: Could not parse relay log event entry. The possible reasons are: the master's binary log is corrupted (you can check this by running 'mysqlbinlog' on the binary log), the slave's relay log is corrupted (you can check this by running 'mysqlbinlog' on the relay log), a network problem, or a bug in the master's or slave's MySQL code. If you want to check the master's binary log or slave's relay log, you will be able to know their names by issuing 'SHOW SLAVE STATUS' on this slave. Error_code: 1594

2016-03-08 15:32:09 1184 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'mysql-bin-log.000820' position 104878880


I searched lots of posts but unable to get a solutions. Does anyone have a solution of it ?

Main thing is that, why it is happening ?

MySQL version: 5.6.24 in windows Platform

Windows server are virtual servers

This happened when system was running in Master - Master replication and Fabric enabled for DR.
Raised the issue to Oracle Support. 

The issue is a bug where Oracle development team is still working on it.

Issue: MySQL Enterprise Backup tries to backup all the binlogs and during that time, internal mechanism cant take backup of binlogs and crashes the DB. Oracle development is still working on the issue.

Workaround: 
Avoid taking backup of binlogs and relaylogs in both incremental and full backup.