When you see 'Failed to scan' warning message during startup process.

[support200]

You may see this kind of message after v4.5.4.1.

org.apache.tomcat.util.scan.StandardJarScanner processURLs
WARNING: Failed to scan [file:/nxfilter/lib/lib/slf4j-api-1.7.22.jar] from classloader hierarchy
java.io.FileNotFoundException: /nxfilter/lib/lib/slf4j-api-1.7.22.jar

This is because you have old versions of library files still remained in /nxfilter/lib. You may need to delete /nxfilter/lib/*.jar and replace them with the files from the newest version. You can get the new JAR files from our ZIP package.