Troubleshooting tips from long time Emacs users.
 Find where a function is defined
- M-x find-function
- This command finds the source file containing the definition of the function near point.
- M-x find-function-on-key
- This finds the source file containing the definition of the function bound to that key.
However, some functions are implemented in C rather than Lisp. To find these functions, download the C source files and add the following to your init file:
(setq find-function-C-source-directory "/path/to/C-source-directory")
 Locate library file
- M-x locate-library
- Use this to debug load-path issues. Try M-x locate-library RET org RET now.
I just got this issue but only on ESXi cluster. I changed the das.failuredetectiontime value on 4 cluster (1 full ESXi's and 3 full ESX's) and only the ESXi cluster didn't update the value.
 Looking at Emacs Lisp files
When installing new packages, you would want to hear some words of wisdom from the author of the library file.
- M-x find-library
- Try M-x find-library RET mediawiki RET to see whether you have installed Mediawiki.el. If it works, look at the Commentary section to see the author's notes.