I am trying to manually rollover a file on demand, I do this using the rollover method of the appender.
When I do this I get the following error:

java.lang.NullPointerException: null
at ch.qos.logback.core.rolling.helper.FileFilterUtil.afterLastSlash(FileFilterUtil.java:46) ~[logback-core-1.0.9.jar:na]
at ch.qos.logback.core.rolling.TimeBasedRollingPolicy.rollover(TimeBasedRollingPolicy.java:126) ~[logback-core-1.0.9.jar:na]
at ch.qos.logback.core.rolling.RollingFileAppender.rollover(RollingFileAppender.java:111) ~[logback-core-1.0.9.jar:na]