Cannot get to Admin panel after moving from XAMPP on OSX to XAMPP on Windows

I have completed a transfer of a SuiteCRM installation from OSX (where I carried out version upgrades) to Windows. I am using XAMPP on both OSs. Most screens spend and seem to be fine but I am getting a fatal error on the Admin panel and I want to execute a rebuild for obvious reasons. Any ideas?

Warning: require_once(Zend/Oauth/Provider.php): failed to open stream: No such file or directory in C:\xampp\htdocs\CRM\modules\OAuthTokens\OAuthToken.php on line 43

Fatal error: require_once(): Failed opening required ‘Zend/Oauth/Provider.php’ (include_path=‘C:\xampp\htdocs\CRM;C:\xampp\htdocs\CRM\include\HTMLPurifier/standalone;C:\xampp\htdocs\CRM\include/…;.;C:\xampp\php\PEAR’) in C:\xampp\htdocs\CRM\modules\OAuthTokens\OAuthToken.php on line 43