What dos it mean: Skipping because it does not denote a directory

My application is working perfectly but I have been facing a lot of Warning
in Spring Tool Suite like:

[WARNING ] Skipping
[C:\Users\e049447\.m2\repository\org\apache\httpcomponents\httpcore\4.1\httpcore-4.1.jar]
because it does not denote a directory

What does it mean? I can see the jars in the correct place and I can run
the code which depends on httpcore normally.