I tried deleting the /core/cache directory and clearing my browser cache and cookies. I also tried turning off commpress_js and compress_css in the DB. Neither of those worked.
When I view the console log in Fire Bug I notice a few common occurrences.
First I see this logged as a syntax error:
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<b>Warning</b>: include_once(/my/old/file/path/core/model/modx/modx.class.php): failed to open stream: No such file or directory in <b>C:\xampp\htdocs\mysite\connectors\index.php</b> on line <b>28</b><br />
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<b>Warning</b>: include_once(): Failed opening '/my/old/file/path/core/model/modx/modx.class.php' for inclusion (include_path='.;C:\xampp\php\PEAR') in <b>C:\xampp\htdocs\mysite\connectors\index.php</b> on line <b>28</b><br />
I get this despite having updated my /config.inc.php, /manager/config.inc.php, and /core/config/config.inc.php files as well as the modx_workspaces table with my new core path.
I also consistently notice type and reference errors showing certain javascript entities as undefined whenever I click one of the manager top nav links.