Cannot reload Confluence webapp inside Tomcat Manager

java.lang.NullPointerException
at java.lang.System.arraycopy(Native Method)
at java.lang.AbstractStringBuilder.getChars(AbstractStringBuilder.java:331)
at java.lang.StringBuffer.getChars(StringBuffer.java:202)
at org.apache.log4j.helpers.ISO8601DateFormat.format(ISO8601DateFormat.java:120)
at java.text.DateFormat.format(DateFormat.java:314)
at org.apache.log4j.helpers.PatternParser$DatePatternConverter.convert(PatternParser.java:436)
at org.apache.log4j.helpers.PatternConverter.format(PatternConverter.java:56)
at org.apache.log4j.PatternLayout.format(PatternLayout.java:495)
at com.atlassian.confluence.util.PatternLayoutWithStackTrace.format(PatternLayoutWithStackTrace.java:30)
at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:292)
at org.apache.log4j.WriterAppender.append(WriterAppender.java:150)
at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:221)
at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:57)
at org.apache.log4j.Category.callAppenders(Category.java:187)
at org.apache.log4j.Category.forcedLog(Category.java:372)
at org.apache.log4j.Category.warn(Category.java:1019)
at com.atlassian.confluence.setup.BootstrapUtils.getBootstrapManager(BootstrapUtils.ja