We are trying to migrate from log4j to slf4j. During the process we use the log4j-over-slf4j bridge. In this bridge following error occurs:

If an entry is logged with priotory Level.ALL,
logger.log( Level.ALL, "log entry to all" );,
the follwing exception is thrown:

Exception in thread "Thread-6" java.lang.IllegalStateException: Unknown Priority ALL
at org.apache.log4j.Category.priorityToLevelInt(Category.java:325)
at org.apache.log4j.Category.log(Category.java:305)