Upgrading to Symfony 1.2 - Fatal error: Class '' not found

[nwbrd]

Hi All,
Currently I am upgrading from Symfony 1.1.9 to 1.2.12. It gives me below fatal error while I am trying to build forms as a part of upgrade using the command $ php symfony propel:build-forms

Fatal error: Class '' not found in E:\Project\lib\symfony-1.2.12\lib\plugins\sfPropelPlugin\lib\generator\sfPropelFormGenerator.class.php on line 86

Please help if any one encountered the same error before

Regards,
Nwbrd