“CLI has stopped working” is an error that you may encounter when running command-line PHP scripts in Windows.  This has been reported frequently by CakePHP users when their “bake” scripts crash.  My particular experience with this issue occurred while running PHPUnit tests from the command line.

The top search result as well as others indicates that this is a problem with php_mysqli.dll however none of the suggestions on this page helped me.  An experts exchange post indicates that the problem is with libmysql.dll, however I didn’t know where to download the replacement for libmysql.dll.  It turns out that I already had it and the following solves the problem on My Vista and Windows 2003 boxes:

Copy From: C:\Program Files\MySQL Server 5.0\bin\libmySQL.dll

Paste To: C:\Program Files\PHP\ (overwrite the original)

This assumes you installed MySQL and PHP to their default locations.  If not, then use the correct paths for your particular setup.

Prior to this fix, my unit tests were causing the “CLI has stopped working” error at least 50% of the time.  Since replacing the dll file I haven’t seen the error.