I have just install slime in emacs. And after removed all the other plugins for debuging, I found that slime seems had conflicts with autopair.(Or a bug of autopair?).In slime, when I typed C-c C-c, the minibuffer displayed error like:

error in process filter: define-key: Wrong type argument: characterp, nil
error in process filter: Wrong type argument: characterp, nil
error in process filter: define-key: Wrong type argument: characterp, nil
error in process filter: Wrong type argument: characterp, nil

Even more, the error message still alerted after I killed the slime buffer.

If I also remove the autopair plugin, slime works just fine. Can anyone tell me how to solve this? Thanks. :)