Exception when using log4j2.properties and logger with dot

After upgrading log4j2 from 2.5 to 2.6 I get the following exception:

Exception in thread "main" org.apache.logging.log4j.core.config.ConfigurationException: No name attribute provided for Logger org
at org.apache.logging.log4j.core.config.properties.PropertiesConfigurationBuilder.createLogger(PropertiesConfigurationBuilder.java:215)
at org.apache.logging.log4j.core.config.properties.PropertiesConfigurationBuilder.build(PropertiesConfigurationBuilder.java:140)
at org.apache.logging.log4j.core.config.properties.PropertiesConfigurationFactory.getConfiguration(PropertiesConfigurationFactory.java:52)
at org.apache.logging.log4j.core.config.properties.PropertiesConfigurationFactory.getConfiguration(PropertiesConfigurationFactory.java:34)
at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:510)
at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:450)
at org.apache.logging.log4j.core.config.ConfigurationFactory.getConfiguration(ConfigurationFactory.java:257)
at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:560)
at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:577)
at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:212)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:152)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:45)
at org.apache.logging.log4j.LogManager.getContext(LogManager.java:194)
at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getContext(AbstractLoggerAdapter.java:103)
at org.apache.logging.log4j.jcl.LogAdapter.getContext(LogAdapter.java:39)
at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getLogger(AbstractLoggerAdapter.java:42)
at org.apache.logging.log4j.jcl.LogFactoryImpl.getInstance(LogFactoryImpl.java:40)
at org.apache.logging.log4j.jcl.LogFactoryImpl.getInstance(LogFactoryImpl.java:55)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:655)
at org.springframework.context.support.AbstractApplicationContext.<init>(AbstractApplicationContext.java:159)
at org.springframework.context.support.AbstractApplicationContext.<init>(AbstractApplicationContext.java:223)
at org.springframework.context.support.AbstractRefreshableApplicationContext.<init>(AbstractRefreshableApplicationContext.java:88)
at org.springframework.context.support.AbstractRefreshableConfigApplicationContext.<init>(AbstractRefreshableConfigApplicationContext.java:58)
at org.springframework.context.support.AbstractXmlApplicationContext.<init>(AbstractXmlApplicationContext.java:61)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:136)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
x.y.z.Start.main(Start.java:12)

The parameter "key" has the value "org" and the parameter properties has the value

{activiti.engine.impl.level=info, activiti.engine.impl.name=org.activiti.engine.impl}

The log4j2.properties in use:

# Root logger option
rootLogger.level = info
rootLogger.appenderRefs = stdout
rootLogger.appenderRef.stdout.ref = STDOUT

# Redirect log messages to console
appenders = stdout
appender.stdout.type = Console
appender.stdout.name = STDOUT
appender.stdout.layout.type = PatternLayout
appender.stdout.layout.pattern = %d %-5p [%t] %c - %m%n

Sadly I have not been able to reproduce the issue in a simple standalone application.