The cl-asdf package is very old (lower than 2.27) and since quicklisp loads its own asdf asdf throws an error and unloads. The package should be updated ASAP since quicklisp is used by pretty much all Common Lisp users (apart from some purists)
@Reporter: Could you please include the command and error output asn attachment please
(In reply to KSP Atlas from comment #0) No. the cl-asdf is not old. It's quite new. The warning message will appear if you use sbcl or ccl to load a cl- related package. It stems that those common-lisp implements have their own asdf, and will check if there is asdf.asd in the asdf:*central-registry*. If there is, a warning message appears. It does not matter with the version. An empty file can also raise the warning.
removing /usr/local/lib/common-lisp/system-registry/asdf.asd may fixed the annoying warning about "...have an older version of ASDF (and older than 2.27 at that)..." in fact, any "asdf.asd" should not exist. we load asdf into an implement by loading asdf.lisp itself other than through asdf.asd.