I'm specifying my compass.engine.connection = "mmap://C:/my_index" in an attempt to use MMapDirectory. Compass's DefaultLuceneSearchEngineStore.configure() uses the connection protocol to determine which FS store to instantiate. However, FSDirectoryStore.configure() only strips protocols of "file://" when it should also strip "mmap://" or whatever else when determining the indexPath. Because it does not strip the protocol for mmap, it then attempts to open a File( "mmap://C:/my_index" ) which fails with the exception below. org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'compass' defined in class path resource [org.photogoodness.client.core_spring.xml]: Invocation of init method failed; nested exception is org.compass.core.engine.SearchEngineException: Failed to open directory for path [indexversionsearchentry]; nested exception is java.io.IOException: The filename, directory name, or volume label syntax is incorrect Caused by: org.compass.core.engine.SearchEngineException: Failed to open directory for path [indexversionsearchentry]; nested exception is java.io.IOException: The filename, directory name, or volume label syntax is incorrect java.io.IOException: The filename, directory name, or volume label syntax is incorrect at java.io.WinNTFileSystem.canonicalize0(Native Method) at java.io.Win32FileSystem.canonicalize(Win32FileSystem.java:396) at java.io.File.getCanonicalPath(File.java:559) at org.apache.lucene.store.FSDirectory.getDirectory(FSDirectory.java:168) at org.apache.lucene.store.FSDirectory.getDirectory(FSDirectory.java:139) at org.compass.core.lucene.engine.store.FSDirectoryStore.open(FSDirectoryStore.java:70) at org.compass.core.lucene.engine.store.DefaultLuceneSearchEngineStore.openDirectory(DefaultLuceneSearchEngineStore.java:282) at org.compass.core.lucene.engine.store.DefaultLuceneSearchEngineStore.indexExists(DefaultLuceneSearchEngineStore.java:377) at org.compass.core.lucene.engine.store.DefaultLuceneSearchEngineStore.verifyIndex(DefaultLuceneSearchEngineStore.java:444) at org.compass.core.lucene.engine.store.DefaultLuceneSearchEngineStore.verifyIndex(DefaultLuceneSearchEngineStore.java:440) at org.compass.core.lucene.engine.store.DefaultLuceneSearchEngineStore.verifyIndex(DefaultLuceneSearchEngineStore.java:432) at org.compass.core.lucene.engine.manager.DefaultLuceneSearchEngineIndexManager$4.doInTransaction(DefaultLuceneSearchEngineIndexManager.java:136) at org.compass.core.lucene.engine.manager.DefaultLuceneSearchEngineIndexManager$4.doInTransaction(DefaultLuceneSearchEngineIndexManager.java:134) at org.compass.core.impl.DefaultCompass$CompassTransactionContext.execute(DefaultCompass.java:310) at org.compass.core.lucene.engine.manager.DefaultLuceneSearchEngineIndexManager.verifyIndex(DefaultLuceneSearchEngineIndexManager.java:133) at org.compass.core.impl.DefaultCompass.<init>(DefaultCompass.java:145) at org.compass.core.impl.DefaultCompass.<init>(DefaultCompass.java:107) at org.compass.core.impl.DefaultCompass.<init>(DefaultCompass.java:100) at org.compass.core.config.CompassConfiguration.buildCompass(CompassConfiguration.java:232) at org.compass.spring.LocalCompassBean.newCompass(LocalCompassBean.java:336) at org.compass.spring.LocalCompassBean.afterPropertiesSet(LocalCompassBean.java:326) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1198) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1167) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:427) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:249) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:155) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:246) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:285) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:352) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:122) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.ja