PHP Fatal error Class 'CRM_Extension_ClassLoader' not found in civicrm/civicrm/CRM/Extension/System.php:196
Sorry, I finally found the solution.  It was incredibly simple but hard to find.  When I uploaded the new version of civicrm using FileZilla, it said all transfers were successful and 0 failed.  However, there were a few files, one being ClassLoader.php, that were 0 in File Size.  It marked it as successfully uploaded, but didn't upload any content.  I just used FileZilla to upload all files again with the option to only Overwrite if the size was different, and it fixed these errors.