Hi, Morris: Thanks for the instruction. I have recovered from the problem using: 1. delete file : ~/.emacs.d/elpa/archives/melpa/archive-contents 2. add in ~/.emacs the following (package-initialize) (package-refresh-contents) Now I tried to reproduce the problem by reverse back my emacs, but cannot. I am ok if you close the bug. I will let you know if I reproduce it later. best regards, wxie On Wed, Jun 8, 2016 at 5:33 AM, Glenn Morris wrote: > > > 1. start emacs > > 2. M-x list-package > > 3. scroll to org (installed 20160606), mark D, then X > > 4. org is deleted in the installed list > > 5. C-x C-c to exit emacs > > 6. start emacs > > 7. M-x list-package > > 8. error: package-read-archive-contents: Wrong type argument: arrayp, nil > > Thanks for the report. I can't reproduce this. Please repeat, but before > step 7: > > 6b. M-x load-library package.el RET > 6c. M-x toggle-debug-on error RET > > and then after step 7 send the resulting backtrace. >