First you have to make that module error free and update that module from terminal in you are using ubuntu.

You can update module from terminal by -d your_database_name -u your_module_name options.

For example:

python openerp-server ../addons,../openerp-web/addons -d my_test_db -u my_custom_module

Here, -d means database -u means update

This options will update my module in OpenERP database.

You can find more options by --help.

Instead of that the esay way is to just delete or move the module folder from addons folder and then restart OpenERP server and try to log in. You will be able to login easily! :)