the class org.apache.uima.resource.impl.ResourceManager_impl create its own UIMAClassLoader in many methods setExtensionClassPath*().
The method destroy() must be responsible for calling UIMAClassLoader#close() inherited from URLCLassLoader.
It is not the case.
Warning some UIMAClassLoader are shared between many ResourceManager_impl because of ResourceManager_impl#copy()
The inconvenient is that the opened resources like jar file stay locked.